Morse had suspected that his sister, Mouette, would try something foolish after she had been released from the hospital after loosing her baby in an assault from her husband. Of course, he thought it would be to kill her husband. He never considered she might try to kill herself.
He jumped in after her that night on the beach. The sea's darkness made it impossible to find her, but he wouldn't give up. His lungs burned with the effort and more than once he swallowed water. When at last he had given up, he found he no longer had the strength to swim back; the sea took him in.
Like a flash of light it came; the sea lifted him up and he took a deep breath of air. Floating next to him, he saw Mouette and, to his surprise, a seal. His sister was unconscious and, in his delirium, he could have sworn the seal was supporting her. Then he, too, lost consciousness.
He awoke on the beach with Mouette in his arms and that is how Ondine found them. He found his sister's acceptance of their situation alarming. He instinctively trusted Ondine, but he was reticent to throw away his entire life, a good job in computer programing, his apartment, everything, just to go and be with them. He realized he was no longer the same person but a part of him didn't want to move on. Mouette finally convinced him.
Morse has a charming, fun-loving personality, but he is prone to fits of depression that can last for days. Older than his sister, he feels responsible for her and carries a profound guilt at her loss. It tears him up that he cannot find a solution to her sadness. He should have helped her get away from that man long before anything so tragic could happen.
He has idea after idea for changes to the freehold. He wants to bring in into the twentieth century. Having studied and worked with computers all his life, he misses the greatly. He has been chipping away at Ondine to allow him to set up a computer in the freehold. So far, their leader has resisted. She fears the Banality that the machine will bring, despite Morse's reassurance to the contrary.
He still wears linen trousers and button-down shirts over a white t-shirt in the style he used to wear to work. He bears an uncanny resemblance to his sister: the same skin, hair, and eye color. He loves his seal form and uses it to seduce selkie women; snuggling up to them and tickling them with his whiskers. He also plays with the selkie childlings in his seal form. They run away from him down the beach, giggling as he pokes them with his nose in the own special game of tag.
Morse has few regrets about leaving his old lifestyle behind. He loves the new freedom he has acquired but believes that he could improve the lives of the other selkies if Ondine would let him bring a computer into the freehold. He doesn't see computers the way she does. They don't breed Banality, they educate and enrich and link people to other people. He knows he could truly benefit the selkies if only Ondine would let him.
He feels terrible about his sister. He had always been her protector and felt particularly jealous when she married an overbearing husband. He was cut out of her life and he suspects this is why he never took any action to help her. Her rejection caused him to react somewhat vindictively when he knew she needed him. At the time, he told himself that she had asked for it. After all, she hadn't listened to his warnings. These feeling horrify him even though he can't stop them. The guilt he carries comes from this. Now, he trues not to resent her sadness, helping her in any way he can.
He carries a Seaweed Garrote like many of the selkies carry.