At the meeting, the group asks about Selim Hassan. Alak-Begam mentions that the shocktroopers have determined he was killed by a blow to the side of the head (and looks around guiltily; David spots that he’s glanced towards his sewer kit, apparently rarely used, with boots, helmet and long torch), with the dagger to the heart being a post-mortem wound. As the group continues on this thread, he becomes impatient, saying that he knows nothing more about Selim Hassan.

He’s interrupted by a phone call; he answers it, then listens in silence for half a minute and puts the phone down. He gets up, ignoring the group, and walks out of the office; they follow, and when he seems to be making a run for the fifth-floor window Thorfin tackles him to the ground. Once he’s brought out of his trance he’s more willing to talk. The Fire Opal is associated with the pharaoh Akhenaten, who abandoned Egyptian polytheism for worship of a single sun-god Aten; it has the power to control minds. Alak-Begam “found” it in a storeroom (he’s clearly lying), tested its power, and was planning to dominate Overgovernor Natatiri at the ball – but she didn’t show up.

He reckons he knows who arranged for it to be taken: Solomon Beguin, who runs Emco Industries, a local electronics manufacturer. He went to see Beguin after he’d obtained the Opal, but before he’d tested it, and Beguin may have read something in his manner. Also, while he doesn’t remember the phone call at all, his secretary confirms that it came from Emco. Alak-Begam describes Beguin: a huge man, the despair of tailors everywhere.

Emco’s plant is in the city of Omdurman, just across the Nile. The group heads over there; it seems practically shut down, with only a couple of guards at the gate and a few more moving occasionally between buildings. They wait until darkness, then Diamond flies the others over the fence behind one of the buildings, out of sight of the guards. Only one building has any lights on, and they investigate that first; it’s offices, with one man working late. They look through the place, and find a room with a large chair; there’s also a lift door, though there wasn’t one on the floor below.

It’s secured with an electronic lock of sorts, using valves and Nile Empire weird science, but David’s able to get through it. The lift rattles and scrapes as it descends below ground level. The door opens onto a cavernous warehouse space, unlit except by a ring of candles surrounding a vast man, presumably Beguin, who’s holding a red glowing gem in his left hand. He looks as the heroes, sneers, and gestures.

As they advance on him, they run into what feels like an invisible wall. They’re shot at with a pistol, not by Beguin, and can’t immediately tell where the gunfire is coming from. Thorfin puts up a reality bubble and pushes his way through the wall; Diamond and David look around and spot a dark figure concealed in the beams of the ceiling. Diamond unloads with her pistols, and he falls to the ground.

Everyone feels pressure on their minds, though Diamond gets the most of it; they’re all able to resist. Beguin rants about ruling “not only your minds, but those of all of Khartoum! This place and all its people will be mind to command, and then the mighty Dr Mobius will have to bow before me!”

Bullets fired at the invisible wall are deflected, but Diamond fires a spread to see just how they twist, then makes a concerted attack on Beguin. Even with possibilities to spend he’s unable to prevent the damage, and slumps to the ground.

Beguin is unconscious; the other is dead. Diamond takes his dark-vision goggles, as they’re within her native axioms unlike the Nippon Tech night-vision devices she’s been using so far.