Sleep No More (Analog August 1965). Telzey is still in danger from the source behind the spook attack—seemingly to trap a psi—but this time she is menaced by a teleporting creature. What happens when a psi creature is tricked into materializing inside solid rock? We find out. Reprinted in The Lion Game (DAW #38 1973, British hardcover from Sidgwick and Jackson, 1976).