A Call to Arms — Loren L. Coleman

Months have passed since the interplanetary communications net was destroyed, isolating planets across the Republic of the Sphere. Achernar is one of the few worlds still in possession of a working Hyperpulse Generator Station, a device that enables communication across the galaxy -- and a much sought after prize for the splintering factions of the Republic....

After failing to qualify as an active MechWarrior, Raul Ortega finds some solace in the Republic's military reserves on Achernar and dreams of the day he might know the adventure and glory of real combat. The Republic-loyal forces of Achernar are supported by a loose alliance with the Swordsworn, a faction pledged to House Davion, whose leaders have an agenda all their own.

When the planet falls under siege by yet another splinter group, the Steel Wolves, who are intent on capturing the HPG station, Raul is called to active duty. But when the Swordsworn desert Achernar its time of need, Raul discovers that there's li honor in the subtle nuances of treachery and the. brutal realities of war....