After Derek, a Replimoid from the planet Bravenna, is captured and imprisoned by the vampire Roland for almost a decade, Roland shares Derek’s blood with the vampire Rhoshamandes, who drinks Derek’s blood and, through it, discovers that Derek is intimately connected with the spirit of Amel, who betrayed Rhoshamandes and caused the severing of his left arm by Lestat. In anger and retribution, Rhoshamandes severs Derek’s left arm. Unbeknownst to Roland and Rhoshamandes, because Derek is a scientific creation from the planet Bravenna, able to survive immortally through self-replication, Derek’s left arm grows into a perfectly cloned likeness of him. This clone refers to Derek as his father, and Derek accepts him as his son and names him Derek Two, which is immediately shortened to “Dertu.”
Dertu helps Derek escape from Roland’s compound and then helps him to safely reunite with other Replimoids whom the Bravennans have sent to Earth.
Dertu appears in Prince Lestat and the Realms of Atlantis (2016). For more perspectives on Dertu’s character, read the Alphabettery entries Amel, Atlantis, Bravennans, Derek, Kapetria, Katu, Replimoid, Roland, and Welf.