Hal eats the mold
'Help! My son ate this!' she yells in Orin's second and more fleshed-out recollection, yelling it over and over, holding the speckled patch aloft in a pincer of fingers, running around and around the garden's rectangle […] 'God! Help! My son ate this! Help!' she kept yelling, running a tight pattern just inside the square of string; and my brother Orin remembers noting how even in hysterical trauma her flight-lines were plumb, her footprints Native-American-straight, her turns, inside the ideogram of string, crisp and martial, crying 'My son ate this! Help!' and lapping me twice before the memory recedes.
Context
Little Hal has eaten a patch of basement mold; Avril circles the garden screaming the same sentence over and over. Repetition in the mouth, closed laps on the ground — panic running in rings, and even mid-hysteria her turns stay crisp inside the boundary. (The same event gets retold from Orin's side in n.234, p. 1044 — see below.)