Okay, so Rex did bring some new information, after all: a train derailment. There must have been too much smoke for Mark and Happy to see something so obvious. Train derailments have been in the news, lately. The most common causes are student terrorist training exercises gone wild; too many cute bunnies sleeping on rails; and engineers trying to do wheelies.

Don’t buy that? Okay, faulty equipment (poor maintenance) and other human errors are, of course, the actual main reasons. But really, “it wasn’t just an explosion, it was a derailment!” That seems like misplaced drama. Wouldn’t a mysterious explosion be more unnatural, more suspicious, and a more exciting storyline than an explosion because of a train derailment? Ho hum.

If I’m right (and I sometimes am!), the plot hook here could actually be the potential danger of whatever is burning and its effects on the environment. And this would be the justification for Mark and Happy (and maybe Rex) to stick their nose in the railroad’s business.