Lucius Tiberius is a Timecop in a Roman Empire that should not exist. The Roman Empire has stood for more than three thousand years. That fact is well known. What is not so well known is that the Roman Empire collapsed 1,600 years ago.

That was the real world but in the real world someone messed with time. Lucius Tiberius knows the name of the man who changed time and he also knows the location of the time loop in which that man is kept frozen. On Lucius's Time Screen time loops and time possibilities play out. Most of them are fanciful and many of them will never exist but one thing is sacrosanct. Nobody must be allowed to mess with time. For the Romans have glimpsed the other worlds that exist through the portals of time and although Rome exists in almost every time portal, none of the other worlds have Romans in them.

It is the mission of Lucius Tiberius and the other Timecops to police Time and the penalty for traveling through time is almost always death for those who do not work for Time Central. Rome exists in a world that has been at peace for centuries but there will always be those who are disenfranchised or disaffected. The technology for time travel is cheap and accessible to many but those many can be turned into few and the few can be turned into none.

A signal on the Time Field around Ganymede means someone there is building an illegal time transmitter. Lucius Tiberius and three other Timecops travel to Ganymede. Their mission: to find out who is interfering with time and send them to their deaths.