Who is Kay's mentor as noted in the nonfiction book, This Is Going to Hurt?

Hugo is Kay's first registrar when he is a house officer. Having much of the responsibility on the ward, Hugo acts as a sort of mentor to Kay. When Kay witnesses his first death, for example, Hugo takes him out for a cigarette to calm him down. Kay seems to get along with Hugo more than many of these other colleagues, as they share many experiences together on the ward. However, the reader also sees a major difference between Kay and Hugo: while Kay is new on the ward and is excited by new experiences and successes, Hugo has been in the field for much longer and, as a result, downplays much of Kay's excitement.