Four years have passed since Voyager One sent back chilling photos of a spaceship from deep in interstellar space.

A shocked world prepared to meet the Visitors, but terrorism, pandemics, and global political turmoil have now consumed it. Discredited as a hoax, the Visitors have faded from public attention.

But the powerful global conspiracy known as the Triumvirate is behind much of the chaos. Creating a screen of subterfuge and misdirection, they prepare a clandestine welcome for the Visitors, whose origins may be more sinister than the aliens of popular fiction.

Standing in their way are the few brave men and women who foiled the Triumvirate's last attempt to upset the world's fragile balance of power:

Former FBI agent Brad Barnes leads Sentinel, a private intelligence and counter-terrorism operation founded in the wake of the Triumvirate's last deadly plot.

Alex Ephraim - the former Triumvirate assassin known as Mirage - is Sentinel's major weapon against terror.

Matt Ramprakash, former airline pilot and now an officer of the British intelligence agency MI5, is embroiled in a deadly standoff when an airliner is hijacked.

Callie Woolf, once the project manager of the Voyager mission, struggles against the sceptical government's bureaucracy to continue the search for the elusive Visitors as her time and funding runs out.

Sentinel is the only organisation capable of taking the fight to the Triumvirate's door - flexible, unorthodox well-funded and free of government red tape.

But as they pursue the Triumvirate from the streets of London to the wild, deadly wastes of Antarctica, Brad will need Matt and Callie's help to stop the Triumvirate, which has its own plans for putting Sentinel - and especially Alex - out of the picture for good...

Sentinel is the pulse-pounding second instalment in the Voyager trilogy by Carl Rackman

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