Philip hanging upside down in a storage room, below the London Eye. There is a Frenchie there, and once he leaves, Phillip gets free and rams the door with a heavy object, just as Connie comes through.
Once he wakes her up, she takes him up to the Eye, and by now we know they are on the Other Side. Up there Cynthia is waiting for him, to sacrifice him and open the door.
Meanwhile, in a tunnel, Zeitberg is riveted to the transcendent visions he sees through the doubled monocle. As Connie speculates about the role of Philip in the OtherSiders' plan (Tom wondered about its full extent and how the pieces all fit together), they hear an unfamiliar voice nearby.
This is The real, transdimensional Philip Arch, wearing salvage tech.
Together, they go to the Other Side, fightscene some with EC and Cynthia, after which Evil Connie explains their unstoppable plan. Which they try to figure out how to stop.
EC tells them that the invasion is coming from many Other Sides, and they realize that the place to stop this is on their side. They return to the “real” London Eye.
They set up a contraption to stop the Eye from being used, anticipating that the deadline is sunset.
Connie suddenly has a burst of insight and figures that it's not the ferris wheel but rather the London-Oxford-Bristol I-train (The “London I”) that is the center point of the invasion. With just minutes before sunset, Connie figures another mistake in her calculations: factoring in the leylines and the curvature of the Pattern, the center of the invasion is use Philip Arch's world-hopping salvage tech's 16-cells Hexadecachohoron power sources, Haver's maticulous attention to details, Connie's calculations and Zeitberg's mastery of the magickal arts to defend the place, but during calculations Connie figures out that the real center of the invasion is…
They teleport to a slower shadow - hopefully - and the cameras left behind catch the original steam train poping through the Eye.