After first watching and reading Dune Messiah, I believed that Otheym was in on the conspiracy against Muad'Dib. But after reading the novel a second time, and doing some reference in the Dune Encyclopedia*, I'm not so sure.
I now belive that Otheym has been faithful to Paul since the moment he pledged himself to Muad'Dib's fedaykin. Here's my reasoning:
Otheym claims that he moved into the section of Arrakeen, near all the fremen conspirators, so that he could spy on them. He claims he knew of their treachery from the start, and decided to keep tabs on them, should they try anything. After all, Otheym used Bijaz as a tool to tell Muad'Dib the names of he traitors.
Bijaz, is of course evidence against him. The dwarf was used to encode Hayt to kill Paul, and was create by the Tleilaxu conspirators. But after reading some of the midgets back story we learn that he was taken as a spoil of war on a distant planet. This treasure could have been placed for Otheym to discover. The Bene Gesserit have been arranging coincidences like that for millennia, why couldn't someone else do it? Besides, the Bene Gesserit were also involved in the conspiracy.
Finally it was Otheym's house that the stone burner went off in. This is very incriminating. But I believe that the Fremen conspirators knew of Otheym's loyalties and decided to eliminate him. All of the other Fremen conspirators were far from the blast when it occured.
One could argue that Chani was supposed to have been murdered on the way back from Otheym's house. (certainly this didn't happen since Paul knew that it was a face dancer that was impersonating Lichna, and as such, Paul thwarted that plan.) But certainly the Tleilaxu had some operatives waiting in the shadows, waiting to strike. It would be foolish to attack the emperor in Otheym's well lit and open house.
What's your thoughts on Otheym?
*The Dune Encylopedia prepresents an alternate, most fan fic Dune universe. But it does have some factual information.
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