They operate from their field office underneath an archway of the Williamsburg Bridge in New York City in a two-day 'Time Bubble', on September 10 and 11, 2001.

Each novel revolves around a major change in the historical timeline which the team must work together to fix with the help of their 'support units' – cyborgs who can mimic human behavior.

Paul Kramer, a brilliant physicist from the future, has plans to alter the past – to lead Nazi Germany to victory over the Allied Forces and to ensure an ordered World Reich under his rule.

Liam and the team's support unit, Bob, are sent back in time to try and stop Kramer's plans, whilst in the present, Maddy and Sal witness New York altered by the arrival of a time wave, forming a terrifying new reality – an apocalyptic landscape of ruins and savage mutated descendants of a nuclear holocaust caused by Kramer going insane and detonating some weapon of mass destruction.

A firefight ensues, in which Bob is fatally injured, and Kramer & his cohorts die after being shot by the guards stationed outside Obersalzberg.

In the hunting ground of a deadly undiscovered species of predator, they build a camp and try to send messages into the present time, while Maddy and Sal, with the help of the computer Bob try to find and rescue them.

In 1994, Adam Lewis, a British computer hacker finds his name in the Voynich manuscript after decoding a section of it, a code which is almost one thousand years old.

Liam goes to investigate, but when Maddy and Sal attempt to flee a kill-squad sent to hunt down their field office, all of the TimeRiders become trapped in the Roman past.

When Maddy finally unlocks fragments of the secret that Becks has been holding on to, the TimeRiders start to piece together their true purpose.

Racing through time to connect the clues, the team discover a Mayan tribe where an ancient relic provides a vital link to the past...and future.

In a final effort to prevent time travel destroying history, Liam and Maddy jump forward to 2070 to confront the enigmatic Waldstein and prove once and for all if he is friend or foe.