"Mark Phillips" is, or are, two writers: Randall Garrett and Laurence M. Janifer. Their joint pen-name, derived from their middle names (Philip and Mark), was coined soon after their original meeting, at a science-fiction convention. Both men were drunk at the time, which explains a good deal, and only one has ever sobered up. A matter for constant contention between the collaborators is which one.

Originally published as That Sweet Little Old Lady, Brain Twister follows the adventures of FBI agent Kenneth J. Malone as he attempts to unravel the machinations of a telepathic spy. His first problem: how do you find a telepath to catch the first telepath?

Laurence Janifer was a prolific science fiction author, with a career spanning over 50 years. Though his first published work was a short story in Cosmos magazine in 1953, his career as a writer can be said to have started in 1959 when he began writing for Astounding and Galaxy Science Fiction. Janifer's best known work is the "Survivor" series, comprising five novels and many short stories.

In the early 1960s Janifer teamed with Randall Garrett, a prolific contributor to Astounding and other science fiction magazines who is today best known for the Lord Darcy books. In hopes of replicating the success of spy stories such as James Bond (which were hugely popular at the time), the pair decided to combine a traditional spy narrative with humor and extra-sensory perception to appeal to readers of science fiction.

The novella was nominated for the Hugo Award in 1960.

By : Laurence M. Janifer (1933 - 2002) and Randall Garrett (1927 - 1987)