Natsuno's a little surprised Cassandra doesn't know yet. He thought it would be the first piece of information to pass along the cells.

"It was Clarke," he says, quiet and calm like he's talking about the weather. He stands by his friend, but word would get out eventually, and Cassandra is someone he owes the truth to. "She talked to Tayrey before she disappeared, and Tayrey entrusted her with it."