Amos accompanies Jessica on a bus trip to Portland, where she plans to give a speech. The weather takes a turn for the worse, and a worried looking man boards the bus, headed for Portland. As they continue on their journey they break down. All passengers head into a Cafe, as the bus driver remains outside to fix the engine problem. Jessica returns to the bus to collect a book, where she discovers the worried man, dead, with a screwdriver stuck in his shoulder.
There are many fans of the show that would place this episode top of the pile, for good reason. It is a brilliant mystery, has a true whodunit setup. It's dark, stormy, loaded with suspects, the principle cast are all cut off, and there's a big twist at the end. The music is arguably the best score to feature on the show. There are virtually no flaws to this episode, it's a wonderfully interesting cast, the villain has history, he's not just a bad guy upsetting all and sundry, even Amos Tupper shows a level of intelligence, proving he can observe and think, ahead of Jessica.
Every single thing about this episode is spot on, it's brilliant. 10/10