This collection of award-winning science fiction includes a story that was a finalist for the Hugo Awards and one that was voted one of the 10 greatest science fiction stories to appear during the 1990s. In the title piece, a geologist has downloaded the memories of his deceased mentor into a robot’s electronic brain. Together, they bore through the crust and mantle to the very core of the planet Earth. Their work is complicated by a mysterious intelligence deep within the Earth and by the robot’s own emergent humanity. The remaining stories comprise a variety of tales including a story about climbing in the Chilean Andes in which the protagonist is haunted by a ghost, and a tale about a battle-weary veteran who returns from a high-tech future to face his most sinister challenge at home. Contents: ii •  The Robot's Twilight Companion (frontispiece) • interior artwork by J. K. Potter 1 •  The Robot's Twilight Companion • interior artwork by J. K. Potter 3 • Life on the Moon • (1995) • shortstory by Tony Daniel 22 • A Dry, Quiet War • (1996) • novelette by Tony Daniel 44 • Radio Praha • (1998) • shortstory by Tony Daniel 62 • Aconcagua • (1993) • novelette by Tony Daniel 93 • Black Canoes • (1997) • shortstory by Tony Daniel 110 • Death of Reason • (1992) • novella by Tony Daniel 166 • Mystery Box • (1999) • novelette by Tony Daniel 199 • Grist • (1998) • novella by Tony Daniel 258 • The Robot's Twilight Companion • (1996) • novella by Tony Daniel