Mark Philips was the pseudonym used for SF collaborations between Randall Garrett and Laurence M. Janifer. As Mark Philips, they produced SF three novels featuring FBI agent Kenneth J. Malone. The stories originally appeared in shorter versions in Analog Science Fiction magazine, edited by John W. Campbell, in the late 1950s and early 1960s.

Malone lives in a world where psionic powers such as telepathy and teleportation exist. He must cope with them as well as an FBI Director who leaves Malone continually confused about what situation he is being asked to handle and what he is expected to do about it.

Published in Analog as "That Sweet Little Old Lady," Brain Twister finds Malone charged with investigating leaks in a secret government program. For assistance, he recruits a powerful psi from a mental institution who believes she is Queen Elizabeth I of England. The problem is, she may be right. Brain Twister marries SF adventure with slapstick comedy for hilarious results. It was nominated for a Hugo Award in 1960, losing to Robert A. Heinlein's Starship Troopers.