Orphans of the Kraken (Legends of the Space Marines)

With their Chapter all but destroyed by the monstrous tyranids of Hive Fleet Kraken, Space Marines of the Scythes of the Emperor infiltrate a tyranid bioship in search of the gene-seed of fallen battle brothers. But the deeper they get into the living vessel, the more they realise that something is wrong, and more than just deadly bio-creatures lurk in the foetid interior of the ship.