Lester was having his hair cut! I think that what they have done in the past has implications on the present, so we couldn't see that because it will be a huge shock for the team when they all get back. Um...I seem to remember Helen dropped her Hand Held, so presumably Connor and Abby will find that and get home. Then they will work out how to control the anomolies (which has to happen in the near future) and rescue Danny. I'd love for them to go back and find SIR James Lester again, with Claudia Brown in tow!
Since Helen is dead, presumably the Predators won't exist now. Or they won't be quite the danger that they were, unless Helen was a clone, which makes sense, and therefore we'll have an "Ha ha, you thought I was dead!" moment. But I wouldn't rule out a new villain, to keep the series interesting and different. Don't forget, Christine was being set up in a villain type role, so she might take over. And she and Lester join forces - hey, there's an idea. I bet Ben Miller would be happy
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