Tammy tells her mother that she needs to attend a professor/parent meeting. Cassie picks up on the fact that Tammy is actually trying to set her up romantically. Professor Evan arrives and Cassie agrees to go along with it. One of Tammy's old high school teachers calls her, asking her to come to Main Street where the prom is being held. He wants her to help divert any trouble it seems Jonathan may be starting. Left alone with her set-up date, Cassie goes into complete stalker mode. She outlines to Evan what their relationship would be like, all the way from first kiss to honeymoon after one date. She seems to have scared him off enough and she leaves, paying her share of the tab.

At Company, Rick congratulates Coop on his impending fatherhood. Coop admits he will have lots of questions. Rick offers his future help, especially about how to share joint custody in a comfortable way for both parents. Mel and Rick are arguing about a tenant for the garage apartment whom Rick has already agreed to let move in. Mel wonders how he could let a stranger move in so quickly. She wants to have alone time with Rick. She accuses Rick of being such "a Bauer." Rick readily agrees that he is indeed such a Bauer; they take in strays. Josh and Reva arrive, with Josh still on a high about the veterans' project. He and Reva join Rick and Mel at their table. Just then, Rick and Mel's new tenant arrives at the table. It's Dr. McCabe, the man Reva just fired as her oncologist. The Doc and Reva don't divulge their prior relationship. Josh continues his enthusiastic pitch about the treatment center to Rick and Mel. After the others have excused themselves, leaving Dr. McCabe and Reva alone, he tells her without treatment she may not live long enough to see the veterans' project finished.

Elsewhere at Company, Coop is served papers from Alan Spaulding's attorney. They specify that Coop will have no legal claims to the baby and he will have no involvement with Lizzie. Coop is furious and refuses to sign the papers. He goes upstairs to his room. Ava reaches out to knock at his door, but instead, she retreats to her own room. Coop hears her and starts to knock on her door but stops himself.

On Main Street, where the prom is being held, Ashlee, in order to hold onto Jonathan as her "trophy date," starts to tell him how Lizzie was never really a patient at the clinic. Lizzie, just walking by, notices Jon with Ashlee. She pulls Ashlee aside to tell her "Nate" (what Jon's calling himself) is big trouble. Jon, meanwhile, is going through Ashlee's purse looking for clues. He finds nothing. Tammy is trying to reach Jon on his cell phone, but he ignores the call. Jon has been putting liquor in Ashlee's punch and she's been getting tipsy and a bit bold. Jon dances with her to prove he's with her for the evening. Just then Tammy shows up and asks if she can cut in. Ashlee asks if Tammy is Jon's girlfriend. Tammy replies, "No, we're just cousins." When Ashlee goes back to the table, Jon explains he saw Ashlee being harassed at the mall. He decided to help her out by posing as her boyfriend at the prom. Tammy tells Jon it's the last time she shares him with another girl. After a while, Tammy realizes Jon has left and she has to attend to the drunken Ashlee alone.

Lizzie has left the Main Street prom scene to break into the clinic. While she is searching through files, her Grandpa Alan walks in, catching her in the act. He acknowledges he has taken measures to ensure Coop is not involved with the baby. Lizzie says that is perfect because it will only make Coop want to be with her and the baby more. Alan tells her it will be best when Coop is out of her and her baby's lives permanently. After he leaves, Lizzie continues to go through the files. While she is looking, Jonathan shows up to confront her.

Alan-Michael's flunky shows Gus and Harley pictures of Gus detoxing at the cabin. Harley stands up to him and bullies the guy into handing over the pictures, unaware that it was Alan-Michael's plan all along. Meanwhile, Mallet sets up a Caribbean vacation for him and Dinah in their room, but she can't stop thinking about Alan-Michael's role in Ross' death. She sneaks out and goes to see Harley. Dinah asks Harley for Spaulding resources to track Ross's killer, but Harley is afraid to get her company involved in Dinah's vendetta and refuses. Dinah sees it as yet another Harley betrayal. At the same time, Mallet is warning Blake not to pull Dinah into her own scheme to avenge Ross. Blake pretends to agree, then invites Dinah on a spa weekend – which is really just a cover for more snooping. Later, Gus goes to Billy to talk about addictions, and admits that he's talking to Billy because he can't talk to his wife about it. Lizzie swears to Jonathan that the baby isn't his and he is happy to believe her. Meanwhile, Tammy tries to deal with Ashlee, but the girl refuses to take a hint until Tammy admits she's Jonathan's girlfriend. Ashlee retaliates by telling Tammy that Jonathan has some weird fixation on Lizzie Spaulding. Tammy asks Jonathan what the drunken girl was talking about. Jonathan says he let her think he and Lizzie were involved so Ashlee wouldn't get too attached to him. Coop is trying to scrounge up a lawyer to help him take on Alan, when Beth shows up with a proposal. Or rather, one that she believes Coop needs to make....

A Mother's Day Bash at Company goes very bad very fast when Buzz's potato salad can't stand up to the light of day and poisons half the town. They end up at Cedar's, where Reva has just gone to get her cancer records back from Dr. McCabe. While they're all there...Coop gets a visit from his late mom, Jenna, who tries to make him see that marrying Lizzie is not an option (without letting on that she knows the baby isn't his; people in Heaven know everything). Coop doesn't listen and is about to propose to Lizzie...when he remembers Ava and finds he can't do it. But then, Coop sees Ava kissing her date, Jerry. Harley encounters Nadine, who pretends to be encouraging her rise to power at Spaulding while actually demonstrating how the wheeling and dealing is not for her. Nadine makes Harley see that she has turned into Alan Spaulding with blonde hair and boobs! Harley decides to help Dinah look for Ross's killer. Reva talks to Sarah, who, of all the moms, is the most direct and browbeats her daughter to face reality. With Reva agreeing to stop running away from treatment, Sarah turns her attention to Cassie, telling her she needs to learn to let go, of both Jeffrey and Tammy. Later, Nadine and Jenna focus on Olivia. Nadine thinks Olivia would be bad for Frank but good for Buzz, while Jenna doesn't like her for either man. Emma is the only one who can see the ghosts buzzing around her mother, though Buzz suspects he knows who she's looking at, too.

Harley changes her mind and decides to help Dinah search for Ross's killer by putting the Spaulding jet at her disposal just as Jeffrey is grilling Mallet about what he thinks Dinah might do. Mallet is worried but thinks Dinah is safe with Blake at a spa. Meanwhile, Dinah is not at a spa, she is not with Blake and she is not safe. Blake turns up to inform Mallet, Harley, Gus and Jeffrey that her stepdaughter has disappeared. Jeffrey thinks Blake knows exactly where Dinah is and is using her to avenge Ross. Gus tells Mallet that the last time he saw Dinah they both suspected Alan-Michael was on an island somewhere. Harley manages to track down Dinah's flight...as Mallet realizes Dinah stole his gun. Meanwhile, Alan-Michael is relaxing in the tropics, when he comes face to face with a deadly Dinah. Beth blackmails Alan: Either he stays out of Coop and Lizzie's way, or she takes their new baby away from him. She also threatens Alan with what Beth knows about him and Ross's death. Rick overhears. As always, Beth's scheming is a major turn-on for Alan. He grabs her for a hot kiss and asks her to remarry him...at his private retreat in the islands. Later, Rick calls Blake. Billy informs Josh the architect told him that in order to build his veteran's hospital the way he wants to, they'll have to pave over Cross Creek. Josh suggests they simply pick up the cabin and move it instead. Meanwhile, Reva does her research and heads for Colin, declaring it's time to fight her cancer. But she still doesn't intend to tell Josh about it. Reva makes an appointment to start getting radiation.

Rick and Mel stop in to Company for lunch. Rick is very excited with the fact that Leah is coming home from school for the summer. He hopes that she'll decide to stay home for good, but Mel believes their 14 year old daughter is perfectly happy at her school. A little later, the conversation turns to father's and daughters and then to Ross and Phillip. Rick is still sad about Phillip but Mel thinks Lizzie's better off without her father. The conversation also turns to Blake and her running for mayor. Mel thinks it's a great idea, Rick doesn't. Later that day, downtown, Mel tells Rick that she has to work the weekend they're set to go away. When he suggests they cancel, she encourages him to go without her.

Cassie and Billy are on Main Street where Josh is discussing his plans for the H.B. Lewis Center. The pair is discussing Josh and Reva and whether their reconciliation will last. Cassie insists that Josh and Reva meant to be and accuses Billy of being in a rut. She warns him not to mess with her sister's happiness. Cassie tries to convince Billy that he simply mistook Reva's kindness for something else and now he needs to move on. At that point, Josh comes over to them and tells the pair his surprise for Reva--he's having the cabin at Cross Creek brought to Springfield.

Meanwhile, Reva's also downtown and trying to keep to herself so she can mask the pain she's in. Who would she see but her doctor, Dr. McCabe? McCabe is there on behalf of Cedars, at Dr. Grant's request. After goading the doctor a little, Reva walks off and is pulled into a dance by an ecstatic Josh. All of Josh's twirling and dipping is causing Reva pain but she makes an excuse about having bumped into a door earlier. Later, Reva decides she needs to leave and asks McCabe to help her get out of there. The doctor doesn't want to lie for her and insists that she should just tell Josh the truth. Rev won't consider that though--she doesn't want to put a damper on Josh's mood. When Josh comes over, Just then, Josh comes by and Reva tells him that she needs to go to the hospital with Dr. McCabe to go over some statistics for the veteran's hospital. McCabe covers for her by keeping quiet but later reiterates that Josh needs to know what's happening with her.

Dinah's tracked down Alan-Michael -- a.k.a Andrew Matthew Spencer at the Caribbean resort. When she asks what he's doing there, he maintains that he just wanted to be alone and relax. Dinah accuses him of bailing on their deal but Alan-Michael states that's not the case. Dinah then starts talking about how she misses her father and she tells Alan-Michael about the mechanic who worked on Ross's plane. Suddenly, Dinah has a gun aimed at Alan-Michael. She then tells him that Ross's plane was sabotaged and then he and Alan-Michael had several meetings in D.C. That makes him the prime suspect. Alan-Michael tries to tell Dinah that he'd have reason to have Ross killed but she thinks it's possible that Ross had something on Alan-Michael. Alan-Michael insists he had nothing to do with Ross's death and if she kills him she'll lose everything just like when she killed Hart. Dinah's too angry to listen though. The fact that he disappeared when Ross died and the fact that he's at the hotel under an assumed name is too much of a coincidence. Alan-Michael tries to talk Dinah down. Still holding the gun to his face, Dinah tells him she won't shoot him, but he may have an accident just like her father. She starts talking about how all she wanted to do was make her father proud of her. Alan-Michael tells her to think of her mother, and Mallet and everyone else in her life. He warns her again that she could lose everything.

by the look on Dinah's face, she doesn't seem to care.

A frantic Mallet is at the same resort with Harley and Gus trying to locate Dinah. While Mallet heads off in one direction, leaving several messages on Dina's voice mail, Gus and Harley go off in another. At one point, Gus and Harley mention the name Dinah Marler to an employee at the hotel. The man doesn't recognize the picture of Dinah but states that Ross Marler has a suite there. Pretending to be Blake, Harley tells the man of Ross's death. She and Gus then ask to go to Ross' suite on the pretense of collecting his things.

While looking for Dinah, Mallet spots her picture among a montage of pictures a tourist photographer has taken. Mallet pumps the man for information on where he can locate her. Soon after, Mallet finally comes across Dinah who's sprawled on the ground with a gun in her hand. Mallet tells Dinah to tell him what happened. An upset Dinah tells him if she does, he won't ever want to see her again.

In Ross's suite, Harley and Gus find Nicole Flanders' business card. Harley calls the number and talks to Nicole's partner, Kelsey. Kelsey doesn't know the details on the case Nicole was working on but has one piece of information. She faxes a photo over. Harley takes a look at the photo and is shocked by what she sees. She tells Gus she thinks she knows why Ross had to die.