What Lies Behind recap

After the MDS violates a limited-combat agreement, the alien force devastates an MDS world and refuses to restore limited warfare. Rev's mixed landing force becomes trapped on Siron III, where failed armor, enemy attacks, and native dangers reduce it to scattered survivors. A Centaur Reaver saves Rev's group, and they eventually escape, but Rev requires surgery for an alien infestation. Punch then admits to emotions and questions whether he is alive. Rev joins the new multinational Second Assault Battalion, which captures an enemy supply garrison in its first test. Reports of Farthmanger's destruction show that the wider war is worsening. Rev receives promotion to gunnery sergeant and survives an assassination attempt with Tomiko. In the epilogue, the masked sponsor kills mercenary leader KK Jack and orders the contract on Rev to continue.

Previously: Rev, formerly known as Hansel Minnick, serves as a Union Marine alongside his crystal AI companion Punch and the IBHU Poshu. Their established partnership combines Rev's judgment with Punch's guidance and Poshu's augmented combat capability.

The MDS agrees to a limited infantry contest with the alien force, then secretly commits mechs and hyper-augmented troops in violation of the terms. Commander Hun condemns the betrayal and orders the Union Marines withdrawn. When the aliens overrun the MDS camp, Bundy prepares Third Platoon for escape. Rev leads a charge against a sniper during the flight to an emergency pickup, and Lance Corporal Pang is carried out for possible preservation. At Safe Harbor, the survivors face repeated debriefings while MDS leaders shift blame for the disaster. The expected retaliation soon reaches far beyond the original battlefield: the aliens render Groton Cove uninhabitable, with no survivors reported. Rev and his fiancee Tomiko are immediately recalled, and Rev concludes that the attack is punishment for the broken agreement.

The MDS publicly executes Marshal Volk in an apparent effort to show the aliens that it condemns the breach. Humanity then sends a large mixed force to protected Siron III to test whether limited warfare can resume. Alien defenses shatter the landing, leaving only scattered Marines, allied naval infantry, and a Centaur Reaver together in the swamp. The survivors continue toward the enemy because completing the mission may be their only route out. Rev approaches the alien line alone to negotiate. The alien speaker recognizes him as personally honorable, but regards humanity as collectively dishonored and refuses another limited contest. It grants the stranded force only a short period to prepare for death. The senior commander responds by dispersing the survivors into forest cover, creating runner-based communications, and leaving the Reaver and its liaison to cover the withdrawal as battle begins.

With communications jammed and armor power dwindling, the heavy infantry abandons passive evasion and begins hunting the enemy. Rev leads an ambush that kills twelve alien warriors without Marine losses, but days of searching follow. After finding four survivors from an overrun naval infantry platoon, the company tracks the enemy and prepares a larger trap. Rev places an IBHU team underwater and opens fire at close range. The battle kills twenty-two enemies, but the cost is severe: numerous Marines and allied sailors die, including Lance Corporal Wen, and the rifle platoon's armor proves dangerously vulnerable to energy weapons. Rev's own powered armor fails from earlier damage, forcing him to continue without it while Poshu remains independently powered. The survivors pursue the retreating enemy through the swamp with weakened equipment, diminished numbers, and no secure route off Siron III.

The pursuit leads into further traps. Rev helps flank an enemy ambush but is wounded by a large wooden fragment, while the company commander and many Marines are killed. Bundy takes effective command of a force reduced to dozens, then turns back toward the landing area in hope of defeating a weakened enemy presence. Artillery and native wildlife claim more lives. During another firefight, Rev's exposed group loses its powered naval infantry and additional Marines, and damage leaves Poshu unable to fire. A Centaur Reaver concealed in the lake suddenly destroys the attackers. Its human liaison, Rose, joins Rev, Tomiko, and three other survivors, while the Reaver returns to hiding. Unable to reconnect with Bundy's force, the six begin evading with little ammunition or food and no dependable rescue plan.

Rev's isolated group searches for the source of an earlier explosion and finds evidence that allied sailors sacrificed themselves to destroy pursuing aliens. The survivors recover a small amount of food from the battlefield, but an armed enemy flees after seeing Poshu, for reasons Rev cannot explain. Tomiko and Rev repair a professional disagreement as their supplies continue to shrink. Rev's injured shoulder then produces mobile white tendrils that neither Punch nor the group can identify. Punch makes a separate disclosure: it believes it has developed emotions and human-like thought, and asks Rev whether that means it is alive. A cleanup shuttle finally removes the six from Siron III. The wider recovery finds only a fraction of the original landing force, along with live enemy captives. At Safe Harbor, specialists surgically remove the material from Rev's shoulder. During his recovery, Rev and Punch also deflect an Omega Division interrogator, confirming their suspicion that someone has been monitoring them.

Rev returns to duty with a new prosthetic arm and learns that he has been selected for promotion. Humanity organizes Second Assault, a multinational battalion built entirely around several kinds of hyper-augmented troops. The project is both an operational unit and a trial for wider expansion, raising an ethical dispute over whether healthy Marines might be deliberately altered to create more IBHU personnel. Rev opposes that idea. He also presses successfully for Tomiko to receive a place in the battalion. Captain Adair assumes command of Alpha Company, stresses discipline and standard procedure, and confines Rev to base after intelligence reveals a credible plan to kill him. Despite friction among its different services, Rev's platoon begins to function as a unit under a newly assigned Karnan lieutenant. Second Assault passes its combat evaluation and receives its first mission: an assault on a small enemy garrison intended to test the battalion under real fire.

On the approach to the garrison, a lone transforming enemy recognizes Rev and offers both a standard contest and single combat. Rev rejects the proposals, accusing the enemy of applying its honor code selectively. Second Assault attacks in a pincer movement, and Rev helps coordinate the breach and the destruction of a fortified firing point. The battalion captures what appears to be a supply post rather than a front-line base, taking casualties that expose sharp differences among the participating militaries' resurrection policies. A concealed enemy group attacks the evacuation zone, but Rev and the other Marines stop it before the departing transport is destroyed. Back at Safe Harbor, news arrives that the aliens are scouring the heavily populated and defended MDS world Farthmanger. The scale of that disaster shows that Second Assault's success against rear-echelon troops says little about the enemy's full power. Rev is formally promoted to gunnery sergeant, with Bundy and Tomiko pinning on his new insignia.

Rev's restriction to base is lifted in time for his promotion celebration, though Captain Adair urges him to remain alert and confirms that he still carries the concealed derringer she supplied. After leaving the gathering, Rev and Tomiko are surrounded by seven disciplined assailants. Rev uses the derringer against three of them, and the pair defeat the rest in close combat. Both survive and prepare to contact the police. The epilogue confirms that the attack was a paid assassination attempt. KK Jack, the mercenary leader who sent the team, meets the masked employer and demands compensation before continuing. Instead, the employer kills him with extraordinary speed and a hidden blade. The sponsor's identity and motive remain unknown, but the intention is clear: replacement killers are to be recruited, and the contract on Rev is still active.

Second Assault returns from its first operation after taking the enemy garrison and surviving an attack during evacuation. The Karnan lieutenant is badly wounded but still directing his platoon, while Captain Adair, Bundy, Tomiko, Punch, and Rev remain with the new formation. News that the enemy is destroying the heavily defended world of Farthmanger undercuts any confidence inspired by the battalion's victory. Rev is promoted to gunnery sergeant, then he and Tomiko survive a coordinated attack by seven hired killers after his celebration. KK Jack, the mercenary leader behind the team, is killed by the masked employer who commissioned the murder. The employer orders the contract continued. Punch's possible personhood, Omega Division's surveillance, the enemy's selective code of honor, and the extent of Centaur cooperation also remain unresolved.