Beware the unverified condition of the lower-off of Thesaurus. The last third of the pitch has probably not been climbed for many years.
A variation finish exists, giving a more balanced route at around E1 5a; tidied up and led in summer 2014. Once established on the ledge above the second thread, ignore the tempting peg above (on the original line) and step delicately rightwards to reach a vertical crack. Climb the crack, then traverse carefully rightwards to gain and finish up P2 of the Odyssey.
Nick White, Pete Gardner 25/Aug/1987