When a Russian superweapon is let loose under the waves, it's up to President Jack Ryan to find a countermove in the latest entry in this #1 New York Times bestselling series.

US intelligence is reporting turmoil in the Russian navy. Their deadliest submarine, the Belgorod, has unexpectedly launched. Who authorised the departure? What mission is it on? And, most disturbing of all, what weapons do the giant doors on the sub's bow hide?

It's been four decades since a similar incident with the Soviet sub, Red October, ended happily, thanks to a young CIA analyst named Jack Ryan.