Jonas Merrick is faced with one of the biggest moments in his long and illustrious career, as he is tasked with neutralising a Russian sleeper cell that has taken root in London.

Meanwhile, on the other side of the world, a figure from Jonas' past flees for his life alongside his companions in the militia, from out of the Paraguayan jungle towards safety in Brazil.

Can Jonas prevent a devastating breach in British security? And can his old friend escape almost certain death?