“Without a crisis transit, practically none,” the IsoDidact says. “With, about one chance in four. We used them very sparingly during combat engagements.”

“Field situation critical,” Audacity confirms.

“We have a extreme affine solution to the rendezvous point,” the IsoDidact says, “sufficient for our mass … but just barely. Do we take the chance?”

The Librarian hardly hesitates. “Of course,” she says, and grips his arm. “And Mantle’s Approach?”

The IsoDidact prepares a command sequence for the crisis transit. “Solution is fixed. We will make just one jump, albeit a curvy one. Mantle’s Approach will likely follow right behind, sharing some of our curvature.”

“Does that put us more at risk?”

“Of course. I don’t think he cares. Prepare for more than the usual discomfort. Our space-time debt is going to accrue with interest.”

Audacity initiates the sequence. Our jump begins. It is not the worst jump I’ve experienced, but it comes close, and Catalog takes a good hour to recover. The others are also weakened, and Audacity does not respond to my inquiries for an alarming time.

But eventually, the ship returns to full alertness, and we see that we have survived and that we are where we want to be. We have left the galaxy and are now approaching the protected defense perimeter of the greater Ark, set out here in the extragalactic darkness like a gigantic, spiky flower.

The Ur-Didact’s ship follows close, though tentatively.

From a hundred thousand kilometers, the Ark’s central forge is now dark. A single Halo—Omega Halo, our ancilla tells us—remains in parking orbit, aimed toward Path Kethona. It is a fitting name for the last of the Master Builder’s great rings.

Unbeknownst to most, the lesser Ark, hidden a third of the way around the outer boundaries of the galaxy, currently maintains six of its own Halos, intended for a more widespread economical distribution to systems within the galaxy—systems possessing large gas giant planets. These six, alongside a seventh—Installation 07—will serve as a final weapon of last resort, if the greater Ark’s defenses fall short.

A pair of tugs, many times larger than Audacity, takes hold of our hull and Mantle’s Approach, escorting us through layer after layer of detection and deflection shields, spreading in a broad torus around the Ark, which now fills our command center’s display. The IsoDidact and the Librarian study the last great wheel with very different expressions. Then, the Librarian sees a swarm of Lifeworker vessels, tiny by comparison, moored a few kilometers above an otherwise empty petal, with steady illuminated streams of containers moving her specimens down to the Ark’s Lifeworker research station.

“Wonderful!” she cries. “They’ve all survived!”

But as we maneuver and see the giant installation edge-on, there are many more Forerunner ships than we expected, most hidden behind the Ark. Many look damaged, some quite severely.