But she doesn’t respond, still bracketing something we can’t see.

There’s nothing for it. We take a knee and brace for recoil, spend hardrounds to keep her covered. A line of empty eyes emerges from the noise and heat, presses up against one of the cracks to get a bead on us. We can hear its augurs trying to find a lock, almost feel the crackle of its rail, but we’re already drawing level.

Acquire, identify, engage. Shower the halls with shattered plate and broken lenses.

“Hail!” again, as loud as we can make it. “We have to go!”

She drops a shoulder against the wall and presses her weapon through a breach in the metal. We don’t see the flash, but something burns on the other side, tracing the corridor in our thermals.

The shadow of a Mirai staggers back, cold armour outlined with sparks and shrapnel. Hail hits it again before it can find its feet, vaporising the forward contours of its hull. And again, dead-centre, dropping it back into the wall behind it. The hollow thing shrieks as fire finds its magazines, spills cooking ammunition across the deck. A cracked reactor fills the air with static.

With that, Hail comes about, and we keep our aim long enough to get her into cover.

Salt’s Decatur doesn’t move. It holds the line for us, one hand a fist, the other missing at the wrist, its surviving rail crackling with overcharge.

Go well, we send, just as we turn away.

We get a grip on the vault’s huge door, but we need Hail’s help to beat the inertia. Once started, its hinges run smooth as the day they were forged, guiding the slab back into its frame. Even after all this time, these abandoned centuries, it slides into place and finds its locks in a moment. It’s dense enough that it eclipses the screaming nets and bubbling rad, silences the rhythmic hammerblows of the Decatur’s last moments. It leaves us in the dark and quiet, feeling our hulls tick and shiver as they cool.

Hail sways, her machine giving away a little of the shivering jockey in its cockpit. The tips of her rails glow a dull orange, and her vents wheeze steam into the cold, adding a haze to the sterile space around us. Her plates are covered in carbon scores and backblast blisters, the paint bubbling at the edges.

“Salt—” she chokes, just as her breathing gives her space. “Are you—” she swallows. “Are you all right?”

“Still alive,” he groans. “And regretting it already.”

Hail looks at me. “What happened out there?”

“The key wouldn’t fit,” we reply, surprised at the edge in our voice. We don’t mean it to, but it comes out just as bruised and battered as Hail’s does, singed like we’ve been breathing smoke.

“Andrade made a mistake?”

“No. The locks were re-written.”