Same world as I've been talking about before, approximately late-19th century style technology, with magic included. Also, my characters are in a different part of the world than they were before, so I'm also open to ideas that might be new to them.
So two of my characters are traveling together on their quest (they heard a rumor about a drug or herb that they think can help detox their friend (T) who is suffering from nevethe (magic) poisoning, and must pass through a country called Rengroth to get to their destination. The younger prince of Rengroth is a poor excuse for a human being, and my characters stand up to him when he's bullying someone in a tavern. He ends up backing off, but his cronies kidnap one of the two (E) and take him to a pirate island to be sold into slavery. They set things up to make it look like he's dead to his friend (J).
I'm trying to figure out how they might fake E's death, so that J will actually believe it and move on. On the one hand, J will definitely not want to waste time and press on to see if the cure for T amounts to anything. On the other hand, J and E are best friends and have been like family for over half their lives. I don't think he would abandon E unless he was absolutely sure that E was dead, and that there was nothing he could do to save him. Basically, I need J to move on (at least physically from that location, if not emotionally), because there's nothing he can do there,not because he's choosing one friend over another or anything like that.
I considered a poison or drug that would render E unconscious, and would look like death from the outside. But even in that case, if J just sees that his friend is dead, he'd probably want to make sure the remains were taken care of. I think there ought to be some other way to prove he's dead without J seeing the body, but can't think of any.
Rengroth is similar to the Middle East in climate, although probably not quite as technologically advanced as the country J and E are from. I think the prince is less likely to really understand how to use the magic of that world, although I wouldn't put it past him to get some black market drug made with magic or something where the work had already been done for him. He's a somewhat regular visitor to the pirate island, and enjoys himself there regularly.