Dylan McAvoy grew up in Darien, CT, at the same time as Avery and Phyllis Summers. Dylan moved to Chicago with his family when he was in high school. While attending college to become an architect, Dylan's father fell off a ladder and broke his back, so Dylan returned to Chicago to run his father's construction company, which he did for several years. He met lawyer, Avery Bailey Clark when he was doing some construction work at her house. Avery's husband, Joe, had been a workaholic and neglected her. Dylan found Avery crying, and told her not to let her happiness depend on someone else, and they began an ongoing affair. When Dylan's reserve unit got called up, he bought her a ring and asked her to leave her husband for him. Instead, Avery broke it off to work on her marriage. But then Avery's husband found out about the affair, and he divorced her.
In November 2011, Avery received word that Dylan had been killed in Afghanistan, where he had been deployed. Distraught, Avery moved to Genoa City, where her sister Phyllis lived, and where she had done a lot of casework for the Innocence Foundation.
Avery fell in love with Nick Newman. During their courtship Avery told Nick about Dylan and how she had destroyed her marriage for their affair. Nick later found Dylan's dog tags in a jar in Avery's kitchen cabinet drawer. Viewers then saw a man with a duffle bag and in camo attire check into the Genoa City Motor Arms. The man sat on the bed and unfolded a falling-apart journal from which a worn photo of Avery fell. When asked about it later, he said that it contained all of his hopes and dreams. Another time the man was seen digging a boxed engagement ring out of his bag.
With Avery's encouragement to follow his dream, Nick bought a basement bar, started renovations, and named it The Underground, intending to run it with his son, Noah, as bartender. Prior to opening night, a man walked into the club calling himself Mack. Telling Nick he was a contractor, Mack had heard that Nick needed help with some troublesome wiring. Nick asked him if he'd ever done any bartending, and hired Mack to help out, at least on opening night.
On opening night, Avery went to the back, recognized Mac as Dylan and cried, "You died, is this real?" Interrupted by Nick, she told Dylan that she needed to be there for Nick, and they would talk later. The next morning Avery showed up at Dylan's motel and slapped him, asking how dare he come back like that, with no warning? Dylan said he had been injured, returned to Chicago to find her, then found her through the Innocence Foundation, and saw a photo of her and Nick. Dylan claimed he didn't want to mess things up, but just wanted to see her, asked if he should go, and if she loved Nick. Avery left, and told Nick the truth about Dylan, who gave her time to decide who she wanted to be with.
Valentine's Day evening, Avery was stuck at home during a major winter snowstorm, and Nick at the bar. Dylan showed up at her apartment, they reminisced, the power went out, and they kissed in the dark. Nick showed up. Avery tearfully told Dylan goodbye, that she had moved on, and was in love with Nick. Dylan packed and left in his truck on the icy roads, intending to return to Chicago. But Nick's former wife Sharon's car slid on the ice, running Dylan's truck off the road, and he hit a tree, leaving him unconscious. Sharon called for help, and Dylan survived with a concussion and bruised ribs. While in the hospital, Dylan had a flashback to Afghanistan: Dylan was down in the sand, his buddy "Sully" Sullivan was injured. Sully moved to shove his weapon to Dylan and was shot, apparently dead.
Sharon called for help, and Dylan was diagnosed with a concussion and bruised ribs. Dylan went to thank Sharon the next day and found her place with storm damage and her unable to find anyone available to make repairs. Dylan offered his services, and Sharon accepted. Both Avery and Nick were disappointed to hear that Dylan would be staying in town. While Dylan worked on Sharon's kitchen, he told Sharon that his mother had died while he was in the army in Afghanistan. Dylan and Faith became close, and Dylan rescued Faith when she disappeared in the woods. He explained his affinity for children remembering how he had given candy to kids and played soccer to help gain the confidence of the locals. Dylan also told Sharon how a local Afghan family had taken him in after he had been injured, and later how he had rescued their young daughter Ara from an attack and kept her safely hidden for 2 weeks.
After Dylan received word that his dad was getting worse, he moved him from the Milwaukee hospital to Genoa City so they could spend more time together. Dylan explained to Sharon that his father had fallen from a ladder and broken his back years ago, and he had been told that he would never walk again, but he proved them wrong and walked again. But after getting an infection after surgery to get pins replaced, his health had gone downhill ever since. Dylan spent the day talking to his dad about old times, selling his construction company, and his house. His father encouraged him to leave for a couple of hours, and Dylan returned to find that his father had died.
Dylan helped Chelsea Lawson when her car had a dead battery, and they enjoyed each other. Then weeks later, after being yelled at by her estranged husband Adam Newman, and her hopes for telling him about the baby she was carrying were dashed, Chelsea fell into bed with Dylan. Both agreed it was just a one-night stand, and Chelsea knew it would be convenient if she ever had to claim her baby was not Adam's.
Dylan finally told Avery that he could not settle for just friends or be the other man in her life again. On his way out of town, he ran into Chelsea at Crimson Lights and said goodbye. Dylan stopped at a bar, got into a fight with a sheriff's son who had been harassing a woman. Dylan went to jail, and Avery bailed him out. Required to stay in town for his trial, Nick offered Dylan his bartender job again to make money to repay Avery for his bail. Nick also offered to get the charges dropped so Dylan could leave town, but Dylan declined.
Avery broke it to Dylan that she had accepted Nick's marriage proposal. Dylan tried to talk her into marrying him instead, saying that they deserved another chance after all they had gone through. Then Avery asked Dylan if he ever thought about "their baby". Avery said she felt that her miscarriage had been punishment for cheating on her husband. She said that she had lost their baby, then Dylan had disappeared, then she spent two years of misery thinking he was dead, and how she had lost everything. She admitted she had not told Nick about the miscarriage, saying that she could not survive another one, or another failure at love. That Nick was love without pain, and it was too late for her and Dylan. Dylan finally gave up on Avery and sold the engagement ring to repay her for the bail money. Avery begged Dylan not to leave town, but he said that he could not stay and watch her marry Nick, and quit his job at the Underground. He later became a bartender at On the Boulevard working for Billy Abbott.
Adam found out that Chelsea was pregnant, he confronted Chelsea in front of Dylan, and she told them that the baby was Dylan's. Tearing up, Adam told Chelsea he was happy that she was finally having a baby, but apparently it did not matter with whom. After the shock wore off, Dylan assured Chelsea that he would not abandon his child, which Chelsea told him would be due around Thanksgiving. Chelsea felt guilty the more Dylan got into the idea of becoming a father, and invited him over to tell him the truth, that he was not the father. But when he surprised her with plans to build a baby cradle, she backed out again. They began spending a lot of time together, enjoying each other's company while Dylan began designing his new digs in a converted warehouse, including a nursery. Dylan bought Crimson Lights coffee bar, and as they made plans to change its name and personality to make it successful again, Chelsea realized she was falling in love, and she spent the night. The next day, Dylan and Chelsea exchanged "I love you's" while Chelsea's mother, Anita, attempted to tell Adam that he was the father of Chelsea's baby. But knowing Anita only wanted him with Chelsea because he had more money than Dylan, Adam refused to let her talk.
One evening, Chelsea arrived at Dylan's to find 'WILL YOU MARRY ME' scrawled on the wall. Feeling guilty, Chelsea said that she did not deserve this. Dylan left the room, but returned to see that Chelsea had painted her reply of yes.
"Stitch" Rayburn who had been part of Dylan's crew in Afghanistan visited Dylan and met both Chelsea and Avery. Stitch had been a medic, and told how they had met when Dylan busted his chin open falling off a camel. He had stitched Dylan up, and left no scar, so had been called "Stitch" ever since. Stitch told Chelsea that he had been married seven years, with a three year old son. He explained that he had been home on leave after his son's birth when his platoon was massacred, and felt guilty that he should have been there. Alone with Dylan, Stitch suggested Dylan open up to Chelsea about the past. The nightmares returned to Dylan that night, and Chelsea told Dylan that she would be there for him when he is ready to talk about it.
Dylan surprised Chelsea by inviting Jeff and Anita to their place for dinner. Both were visibly disappointed in the place, and Jeff insulted Dylan as not being able to take care of his daughter. But Anita surprised Chelsea saying that Dylan was a good guy, and everything would be all right. They discussed potential baby names of Scarlet, Emily, or Terry after Dylan's dad. After Jeff made some more judgmental comments, Dylan said that he was not Adam and glad of it, because Adam was smart enough to make millions but smart enough to make Chelsea happy.
Dylan finally explained to Chelsea that they had been on a routine mission, but hit a mine that had been planted in the road, causing a huge explosion which killed all of his men. He recalled how Sully had been just a scared kid who was injured in the sand nearby. Dylan had lost his gun and needed one to fight back, so he asked Sully to shove him his gun, but when he moved, Sully was fired on and killed, and it had been Dylan's fault. Somehow Dylan had been rescued by a local family and nursed back to health. But when insurgents attacked the village, the father handed his young daughter Ara to him, and he ran out the back to save her while the family had been slaughtered. Dylan told how they had found what food and water that they could, but Ara's health declined and she had died on the way back to camp. Dylan had been wracked with guilt ever since for letting his unit and the family down, that they were all dead because of him.
Chelsea went into labor, and Dylan took her to the hospital and was at her bedside as they waited for the contractions to stop, as Dylan was led to believe it was too early in her pregnancy. When Chelsea's doctor evaded his questions, Dylan assumed it was because he was not her husband, and suggested to Chelsea that they get married right away. When Chelsea's labor stopped, Dylan took her home to his loft which was decorated for a wedding. The invited guests Chloe, Jeffrey, Anita, and Stitch arrived, followed by Billy with a cake catered by his restaurant. After some quick alterations to Chelsea's wedding gown by Chloe, the minister arrived, heartfelt vows were exchanged, and they were married using Dylan's parent's wedding rings. Afterward, Chelsea again went into labor, and Dylan delivered a baby boy before the paramedics showed up. Chelsea blamed his normal lung development on medication she had been taking and his size on the fact that both she and Dylan had been big babies at birth. They named him after Dylan's father, Terrance Conner McAvoy, to be called Conner. But their happiness was short-lived after Conner was suspected to have inherited retinitis pigmentosa. After Chelsea said there was none in her family, Dylan blamed himself, sure that it must be in his.
Adam confronted Chelsea after overhearing that her baby had a degenerative eye disease like his, but Chelsea still denied that Adam was the father. Dylan arrived, and Adam left, warning her to tell Dylan the truth. Chelsea then had to admit to Dylan that Adam was the father, and that she had known it all along. Dylan teared-up, asking how she could do that to him, let him name the baby after his father, and make him a cradle? Chelsea claimed that she had fallen in love with Dylan, that nothing had to change. Dylan cried that he had loved and trusted her and the baby, but that everything had been based on a lie. Chelsea begged Dylan not to abandon them, but he left. Meanwhile Adam was with Avery asking her to sue Chelsea for custody of his son, and get a paternity test, but she refused.
Avery and Nick's wedding day arrived, but just as she was about to leave for the ceremony, Avery found Dylan sitting on the floor in the hallway outside her apartment. She helped him inside and got him to talk through his distress. Dylan admitted that he had wanted a family so much that he had ignored all the signs, and now he had lost it all. Avery and Dylan then relived the tragic loss of their own unborn child. By the time Avery made it to Chancellor Park, the guests had gone, leaving Nick there alone. After Avery explained, Nick decided that it had become increasingly clear Avery was still too emotionally involved with Dylan. Nick broke up with her, and left her standing there in her wedding gown as it began to rain.
Dylan returned home and told Chelsea that he could not forgive her, was leaving town, and wanted a divorce. As Chelsea left the room, the thunder storm outside intensified. Dylan had a flashback to explosions in Vietnam and ran out the door with Conner. After finding out that his son was missing, Adam went to Avery for help, and they found him with Dylan at his family cabin. Avery talked Dylan down from his PTSD delusion, and he gave the baby to Avery. Avery convinced Dylan to see a psychiatrist, but the man could not relate to PTSD, and Dylan walked out. Dylan's friend Stitch came to his rescue, announcing that they would find him some help from a military doctor, and that he was moving in now that he was a resident at Genoa City Memorial.
Dylan eventually hired Leslie Michaelson to handle his divorce, Chelsea signed, and they wished each other well.
Nikki Newman held a Veteran's Day fundraiser at The Underground to honor the vets. Dylan and Stitch were invited, but Dylan was reluctant to attend. Avery was able to convince him to show up as they reconnected after remembering how much she loved him while he was in the service, and they kissed. Everyone was rather mystified by Nikki's overly friendly gesture of hugging Dylan for having the courage to attend.
Dylan convinced Avery that since they were both finally free, it was their time for second chances, and he set up a romantic date at the Genoa City Athletic Club. But when they arrived, they spotted the Newman family at the table next to theirs. Rather than arouse Nick's ire again, Dylan called around in an attempt to get reservations at another restaurant. But when Nick spotted them together, he unreasonably accused Dylan of following him around and throwing his relationship with Avery in his face. They got in a fist fight, and the other Newmans crowded around in an attempt to break them up. Nikki finally was able to do so by shocking them all by shouting that Dylan was her son. Dylan told her that could not be, that Terry and Penny McAvoy were his parents. Nikki explained that Penny had adopted him as a baby in an attempt to hang onto his father who had never found out. Dylan refused to believe it, and left with Avery. Dylan was further upset when Avery admitted that she had known about it for awhile, and that the facts proved that it was true.