Earth Under the Martians (The Martians Return, #2)

Humanity is on the run.

The second Martian invasion was swift, brutal and decisive. What remains of the human race is in hiding, desperately hunting for a means of defence.

George is determined to keep his promise to Amy: no more heroics, no daring ventures, no unnecessary risk-taking. When their refuge is destroyed, however, they are plunged back into the battle and must make their way to Canada in search of vital materials.

Martian sympathisers, a dangerous sea-voyage, an audacious heist ...