Who is EPICAC from Welcome to the Monkey House and what is their importance?

The only machine in this collections list of characters, EPICAC forms a relationship with the human narrator over the course of the story. At the beginning, EPICAC is working well, but not well enough. It is not until EPICAC begins to talk about human emotion, love and poetry that he starts running quickly and smoothly. EPICAC is built to give and not take, and that is what he does. He devotes all energy to the Pat problem, and when it is solved, and he finds out that he was not writing to Pat so much as for the narrator, he essentially dies of a broken heart.