Cover art
Costello, Matthew J. Time of the Fox. Penguin/Roc 1990.

Costello, Matthew J. Time Warrior
Summary: A graduate student becomes embroiled in US-Soviet timeline conflict.
Series note: Series containing Time of the Fox, Hour of the Scorpion, and Day of the Snake.

Costello, Matthew J. Time of the Fox
Divergence: 1941 CE
Summary: A mental time traveler studying what made the Beatles so great is sidetracked into "change war" action involving Rommel's Afrika Korps.
Series note: First volume of Time Warrior.
Published: Penguin/Roc 1990 (0451450418).

Costello, Matthew J. Hour of the Scorpion
Divergence: 1968 CE
Summary: Our hero becomes a US infantry lieutenant as the time war shifts focus to the Tet offensive and the attack on the US embassy in Saigon.
Series note: Second volume of Time Warrior.
Published: Penguin/Roc 1991 (0451451287).

Costello, Matthew J. Day of the Snake
Divergence: 1941 CE
Summary: More timewar action, involving Pearl Harbor.
Series note: Third volume of Time Warrior.
Published: Penguin/Roc 1992 (0451451708).