I think Isabelles character was pivotal..If she could some how be resurrected on the show as an ally that would be amazing...to see her finally live her life on her terms..to be with kyle and see her father..There are many enemies of the 4400 why should the marked be the only threat?.Lets say the marked in the future have abducted a powerful 4400 to take the place of Isabelle.. this 4400 will stop the progress of Jordan and the occupation of "Promise City"...At one time Isabelle was unstoppable and could heal easily..she failed at several attempts of killing herself..Lets start with the house that jordan and tom exit after Isabelles passing..In a season 5 return she can have an out of body experience that shows her past actions and that of her sacrifice of saving kyle,tom and jordan..only to have isabelles one time enemies from the future, the very ones who asked tom to take her abilites ask for her assistance...a future agent injecting her with a special altered version of promicin to revive her...to make her more powerful and the protector of the 4400..Slipping in and out of consciousness her new future allies show Isabelle her arch rival...Alana.........

My constant vomiting would be amazing. Isabelle has too much history. She has done unforgivable things.

The actress may return playing a different character, and even that would be pushing it, because of the strong feelings about her previous character, but Isabelle as a "good person"? No way.

You know as much as I love Isabelle(mostly in the third season) and I was sad to see her go... It was inevitable, within 2 seasons her character had gone through everything she could there really was no where else to go if they brought her back I think it would be cheap and moslty irritating if they brought her back, its not like she Jordan.

Well, if they want to drop sci-fi and play up the soap opera angle, we could discover that Isabelle had an identical twin, taken by the government at birth and kept secret all this time for no apparent reason. I'm sure no one would roll their eyes at that.

Better yet. Let's clone her. Every season, she can learn humanity in 12 episodes and then die in the finale.

What! You don't think that's possible? I think Ryland would make a great father to Isabelle 2. Oops, I wasn't supposed to roll my eyes.