Always have a backup plan.
The show needs a new villain. The DiMeras are dusty, Clyde is creepy, and the Kiriakises are too busy playing house with Hortons and grifters.
So, we bring in a name actor - maybe Jerry ver Dorn (Guiding Light's Ross; One Life's Clint) or Jordan Clarke (GL's Billy), or Robert S Woods (OLTL's heroic Bo). He's a self-made billionaire who owns TV networks, publishing houses, and property all over the world. His name is Adam Steele.
His company, United Steele, is moving in on DiMera's industry-of-the-week. He even has acquired Steven, Jake, and Peter's shares. He knows a secret about EJ's past that will destroy (ha ha) his career as the DA as well as his marriage to Nicole and his relationship with Johnny. He has information about Alex (he knows about his true paternity) and gets Titan under his thumb. He buys Paulina's building and evicts her. He seduces Kristen and beds Kate (after he sets it up so she thinks Roman's cheating with Marlena). He doesn't like Chanel's donuts. He basically spends 3 months ruining lives around Salem and gloating about it. His early victims make business sense or don't seem that personal, but around the end of the third month, it seems he's got a grudge against the town.
In month four, the denizens of Salem's in-crowd are out for blood, and start trying to make trouble for him - only for him to take off the kid gloves and get really nasty. Marlena is blinded in an explosion (blamed on Steele, but actually an attempt to kill him). Ava tries to seduce him, and then to kill him, only to end up dead herself. Even Kayla works against him after he endangers Stephanie and threatens Joey. It seems he's untouchable, and even the good guys are powerless. However, his relationship with Kristen flourishes, as she seems to relish in the town's destruction, and Rachel likes the guy, too.
In month five, things really get heated. We start rooting for Alex, to whom he's really mean, even though we know he knows he's stealing Xander's inheritance. We're torn with Kayla as she contributes to a plan that could cost her medical license. We even root for EJ to find something on the guy that will bring him down. But there's no light at the end of the tunnel for Salem's core families. Steele starts calling in markers. He outs phony heir Alex, costing him literally everything (even Maggie turns on Victor's grandnephew). Steele now owns Titan and Xander is a pauper again. He's swindled Chad out of the paper, which he is crushing on purpose. He ruins Roman's marriage and when Roman seeks revenge in person, the Pub is blown up. When Paulina and EJ take political action, Steele gets them removed and put in jail for a bribery scheme. Kristen sours on the relationship after a return of her delusion of a reunion with Brady, only to find out that Rachel wants Adam to be her daddy now.
Entering month six, Steele is setting up an elaborate scheme to merge Titan and DiMera, laying off scores of working-class Salemites. Kristen has moved Rachel to a safe location (so she thinks; Rachel immediately contacted Steele). Kayla's research has been completed, and as planned, it is corrupted to poison Steele. The whole town is ready to confront this man who is destroying the city they love; there's a big meeting at City Hall, and Paulina (out on bond) and EJ (in prison blues and cuffs) are allowed to attend. People are out for blood.
As the month closes out, the day of the confrontation comes, and Steele doesn't show up. There's blood in his office and penthouse. Nobody can find Kristen. Paulina has disappeared, as has Marlena. Kate is found in a closet at Steele's with a gunshot wound, and Jeannie T is there, holding a gun. Nobody has a clear picture of what happened, but one thing is sure: Steele is not in Salem anymore, but the repercussions of his actions will resonate for months and years to come.
And he's really gone, for a while at least, until we can find out viewers' reactions. The six-month frame means that nearly everything filmed will be wrapped before it airs, and then if the story works to bring him back after viewers have seen the full run, a new story can be created, leaving space between villainous sprees so the story can be developed as necessary.