Truthsayer Marcus Claire Luyseyal came to Arrakis in 13725 AG with Tertius Eileen Anteac for an audience with the God Emperor that coincides with the Royal Festival held every ten years. They receive a message from Othwi Yake, Assistant to the Ixian Ambassador, that Face Dancers have infiltrated the Ixian Embassy, and are planning to assassinate Leto II.
Anteac and Luyseyal try to warn Leto, but the message does not reach his convoy in time; however, the plot fails, as Anteac and Luyseyal knew it would. They achieve little in their meeting with Leto II, and he takes the priceless vial of spice-essence with which they hoped to test his mortality. He reminds Luyseyal of the lesson learned from past over-machined societies: "The devices themselves condition the users to employ each other the way they employ machines."