Jem was going to be stuck in the past and we'd spend the whole series dealing with him as a man out of time. I was quite relieved that it was more complicated than that and he is learning how to travel in time. That there is a whole society that appears to be doing so makes it even more interesting.
I am very glad that a number of mysteries were resolved by the end with more questions being posed. I am looking forward to the next installment.
Unlike some of the other posts, I didn't hear Douglas Adams type humor here. Maybe I would on a second listen.