Why do his hosts’ clothes always fit? Was everybody into whom he leapt the same shoe size? What happened when he took something off a shelf his host wouldn’t have been able to reach? What about his voice? His eye line? His weight?? It didn’t make any sense!!

The time-travel logic was also incredibly iffy, mixing pre-destiny, alternate pasts, and a constantly adapting timeline depending on the plot requirements. And sometimes the writers threw common sense out the window entirely. In a rare peek into the future at the start of Season 2, Al is sat before a Senate committee arguing for the project’s continued funding. When Sam’s actions in the past cause the sceptical chairman about to shut down the project to be replaced with a more sympathetic adjudicator halfway through the summation, Al somehow notices the switch (no one else, even the senators sitting next to the chairman seem to clock that he’s suddenly turned into a woman). His response to the change suggests that the show runners and/or writers were perfectly happy to sacrifice internal logic if it allowed one of the main actors a great reaction shot. Such inattention to one of the show’s fundamental concepts grated somewhat.

Then there was the not-small matter of why Sam was trapped in this cycle of do-goddery in the first place. As early as the pilot episode it was established that “God or Fate or Time, or something” had hijacked Sam’s experiment and was using him to correct the timeline. It’s a charming attempt to be secular, but each of those options represents a higher power, and the fact that everyone so readily accepts it is frankly baffling for a bunch of scientists. Wasn’t there a chance it was Kevin in IT? Why did no one question if it was the artificially intelligent super-computer overseeing the experiment? After all, it was said computer that came up with the God theory in the first place!

At the very least, this explanation warranted some exploration. I have no issue with spiritual elements informing part of my sci-fi, but hey everyone! You’ve just accepted the existence of God! Shouldn’t you talk about that for a bit?

“A minute ago you said it was crap”

As the seasons progressed, even the character work began to suffer. Chief among the gripes was the writers’ relentless insistence on creating a personal connection between the main characters and an episode’s events. The logic was sound – the stakes are a bit higher when one of our heroes has an investment in how things turn out – but this technique was overused to such an extent that Sam and Al developed back stories that bordered on the comical. Al was an orphan, and a pool shark, and an amateur boxer, and dabbled in a spot of acting, and was a Vietnam vet, a prisoner of war, an astronaut, an alcoholic, was falsely accused of a murder-rape, and had a sister with Down’s syndrome… By the fifth and final season, it was all getting a little ridiculous.