David Hastings is a mystery. When first scene, he was overseas flipping through an American tabloid when he came across a picture of Grace Bennett, whom he seemed to immediately recognize. He quickly came to Harmony, where he began to follow Grace around, and make cryptic phone calls to people, tell them that he had finally found her. When he did finally see Grace, she fainted, and he took her up to his bedroom at the bed and breakfast, where they were found by Sam, who knocked David out, and had him arrested. He refused to say anything at all, but finally blurted out that Grace was his wife! Realising Grace was amnesiac, he told her that they had married in Hartford, and travelled around the coast, until one day she had left him to go to Boston in search of her sister, Faith. He said he received no contact from her in the months she was there, and thought she was dead until he saw her picture in the paper twenty-three years later. He came to Harmony with the hopes of getting her back, but was prepared to walk away when he saw how much in love she and Sam were, and how happy she was with him...until she asked him to stay, which is exactly what he had planned for. He spies on Grace and Sam as often as possible, and his plan is to take Grace away from Harmony and everyone there...his plans for their future in no way include Grace and Sam's three children.
It wasn't long before viewers learned that David wasn't really Grace's long-lost husband at all, but someone hired by Ivy to pretend to be Grace's husband in her latest scheme to break up Grace and Sam. Why he is doing it is unclear, but what we have discovered is that there is some secret in David's past that is so horrible that he will do anything to protect it. Ivy went one step further when she brought David's college-aged son John to town, telling him that Grace was his mother. David was furious, but what Ivy has on him is enough to keep him in line. He hates what he is doing, and has genuinely begin to fall for Grace, but he doesn't want to risk people finding out what he did all those years ago. It's breaking his heart that he is hurting his son, but at least now he has a partner in crime...both he and Eve are being blackmailed by Ivy.
David has been trying to get out from under Ivy's thumb for quote some time as he has truly fallen in love with Grace. He desperately wants a future with Grace, but unlike Ivy, he realizes that what the two of them are doing is wrong, and they will both be truly hated if they're discovered. He was even willing to sign the annulment papers, until a scheming Kay talked her mother out of it. David pushed Grace to take a trip with him to visit all the places they once loved, but when he saw the immense pain she was in when Sam told her it was over, he told her to go back to her husband...he just couldn't continue to cause her this pain. Unfortunately, Ivy will not let him go, and recently, Grace left Sam to be with him and John, honoring what she believes to have been her marriage vows.