Lyra Heartstrings was delighted when she received the assignment to study the rapidly evolving sea life on Pongamus IV for her graduate work. The planet, which was covered in one single, huge ocean, had been seeded with life only 1,000 years before, when ponies first moved to the Pongamus system, but already it was filled with millions of types of fish and sea-mammals. But something sinister is growing in the deep, and when she starts to have nightmares of the watery darkness, Lyra realizes her worst fear: This assignment might be her last.