Gods of Olympus - Neptune's Son

The missing Percy Jackson is back! However, he has lost his memory and does not know who he is, where he comes from, or what his mission is. He awoke from a deep sleep with the she-wolf Lupa, who sent him to Camp Jupiter, the Roman equivalent of Camp Half-Blood. Everyone around him considers him the son of the god Neptune, the Roman god of the seas. Together with other camp members, Frank and Hazel, he travels to Alaska to fulfil an ancient prophecy. Will they succeed in freeing Thanatos, the god of death, imprisoned there by a giant? What other dangers await Percy, whose memory begins to return during his journey?