From the publisher:

When Legionnaire Peter Crogan loses a friend and comrade to a violent sand storm, he is forced to confront some hard questions. Should he wait out the rapidly approaching end of his five-year term of service with the French Foreign Legion, or should he accept an offer of promotion and devote his life to a campaign whose purpose is an enigma to him? Crogan won't have much time to consider his options as he's besieged by the armies of the infamous Tuaregs, under attack from desert raiders, beat down by the relentless heat, and trapped in a cave with a mysterious and terrible creature who is picking off the people in his party, one-by-one. Luckily, he won't have to go it alone! He's but one man in a rag-tag group of hardened fighters, all under the command of a brutally strict sergeant and a dashing captain who may be too brave for his own good... Return to the adventure-prone exploits of Chris Schweizer's not-so-famous fictional family with this new epic volume in the critically acclaimed Crogan Adventures series.