New experiments take Angus under water, to terrifying depths that no man has seen before.
At 16, Angus is the trusted apprentice of Edmond Halley in London, the needle-sharp eye for the successful scientist whose reputation is but growing.
When Halley starts exploring the depths of the sea and comes up with the idea of a diving bell, it is naturally Angus who gets to be the guinea pig sunk down to the bottom of river Thames to test the invention. Would it be possible to live under water?
Reaching adulthood, Angus struggles to figure out who he really is and where his place is in the world. Dreaming of a great future, Angus follows Mr Halley on a long sea journey, heading back to the Southern hemisphere of his home island. Will he get a chance to come onshore St. Helena again?