The letter discusses: 1) Wood's work on proarrows. 2) Resemblence of i : T-Alg -> T-Alg to Wood's situation which suggests the question of the adjoint to i. 3) Kan arrows in Street–Walters sense. 4) Does W left adjoint to Z left adjoint to Y imply A isomorphic to [B^op, Set] where Y is yoneda for A. (Remark: R. Walters believes locales give a counterexample to this.)