At first glance the concepts of time and of Petri nets are quite contrary: while time determines the occurrences of events in a system, classic Petri nets consider their causal relationships and they represent events as concurrent systems. But if we take a closer look at how time and causality are intertwined we realize that there are many possible ways in which time and Petri nets interact. This book takes a closer look at three time-dependent Petri nets: Time Petri nets, Timed Petri nets, and Petri nets with time windows.

Talon, the lone survivor of a race called the Blackbloods, sets off to the edge of civilisation to track her family's killers. On her journey she discovers she has supernatural powers which she must learn to harness in order to achieve her goals.

Shortly after the start of World War II, a ukelele player (George) takes the wrong boat and finds himself in (still uninvaded) Norway. He is mistaken for a fellow British intelligence agent by a woman (Mary), and becomes involved in trying to defeat Nazi agents.