The 11th Book in the Dark Corps Saga. After what has been a long and dangerous journey, Timmy Barnes has reached the final stretch between himself and Ice Base Delta, where his father, the world-famous scientist Dr. Barnes, is being held prisoner by the Dark. Along with his best friend Anna and the five armored members of Bear Company, Timmy will have to cross miles and miles of desolate tundra to reach the underground base. Luckily they have Winter Watch to guide them, a roughneck team of the Dark Corps built to withstand the freezing Arctic temperatures. But even though the path looks clear, danger and peril awaits them in strange forms. Meanwhile, miles away, Reese and Gertrude seek out unlikely allies in their fight against the Agency, and form a plan to help the gathering Dark Corps finish off the threat to our world once and for all.