I'm more on the no side for the Keens to reunite once again. Tom stands for everything Liz hates and what, she should put that all aside just because he was her husband? Their entire relationship was based on a lie. I think Liz would be more of a hypocrite if she gets back with Tom and as others have mentioned, she would be considered weak as a character to choose love over principle. To those who think this is a drama and that's your reasoning, remember emotions are emotions so no matter how fucked up the reality of a TV show is, you can always relate to a character. I really hate that argument: it's a drama, so let it happen. If a drama stops making sense then it's no longer a good drama anymore.
Had to get that off my chest. Case-of-the-week starts now. So a regretful scientist was experimenting on human beings so he could fix up his fiancee. Yet, he told his supervisor that he was working on a way to extend human life. Everything needs to die people. Nothing should last forever. Anyway, Red wanted the scientist because Red thought he could help Liz remember what she had forgotten, which would lead him to the fulcrum (even though Liz already found it). But his results were made up so his superior wouldn't defund him, but since nothing was working, he offed himself.
In other news, Cooper found out just how much power Connolly has. I'm pretty sure Connolly was behind Cooper almost being kicked out of the clinical trial. Sad part was Cooper backed down from his threat. I don't like scared Cooper.