Another subject in which more information was brought to light was that of Jenner. In the first book it was hinted that Jenner had died, but in an event prior to those of the book. Jenner had disagreed with Nicodemus over leaving the city, and took a group of separatists to start a new colony. In the end of the first book, it is revealed that NIMH had found a number of unusual rats dead, and it is assumed that this is Jenner's group.