Rattlesnake by Andy Maslen

Synopsis:

When SAS veteran Gabriel Wolfe receives a five-word text, his self-imposed exile in Hong Kong comes to an abrupt end.

Honouring a blood oath he swore with Vinnie Calder, Gabriel investigates how the ex-Delta Force sniper ended up dead in the middle of the Texan desert.

What he discovers shocks the battle-hardened soldier to the depths of his soul.

Assisted by biotechnology tycoon, Clark Orton, a deniable CIA team is planning to trial a new biological weapon on Cambodian orphans.

Operating alone, Gabriel traces the plot to the heart of the Cambodian jungle. But powerful people want Gabriel silenced, permanently. And they’re happy to use any means necessary to protect their asset.