Rats are curious by nature. When Wainscot, a land rat, follows his curiosity and trespasses in the chambers of his clan's ruling council, he is discovered and forced to flee for his life. Pursued by the relentless C'law - the enforcers of the council's laws - he escapes by boarding a warship, the frigate HMS Heloise. Once aboard, Wainscot is lost, alone, and out of his element in a bewildering and brutal new world. There he meets Moon, a rat of the ship. Like him, she is alone, having been cast out of her own clan. Together, the two struggle to survive the many perils of the Heloise: men, cats, and the two rat clans engaged in a vicious war for domination of the ship. As the Heloise plays her role in the War of 1812, Wainscot and Moon are swept up in the conflicts of both men and rats, and battles burn from the gundecks to the depths of the holds, threatening the fragile home that the two fight to make for themselves. Exciting and moving, Wainscot on the Heloise takes a thrilling journey through a secret world of rats, as Wainscot and Moon face overwhelming odds in their to replace the families they have both lost.