Matthias sighed. "Kings and nobles." He took another drag at his cigarette, and Mike forced himself to stifle a cough. "Noble houses rise and fall on the basis of their wealth. These six, they are not old. They date their fortunes to the reign of-no, to the, ah, eighteen-fifties. Before then, they were unremarkable merchants-tinkers, really. Traders. Today they are the high merchant families, rich beyond comprehension, a law unto themselves. Because they trade. They come to this world bearing dispatches and gems and valuables, and ensure that they arrive back in the empire of the Outer Kingdom-in what you would call California, Mexico, and Oregon-the next day. Without risk of disaster, without delay, without theft by the bands of savages who populate the wilderness. And the trade runs on the other side, too."

"How do they do it?" Mike asked. Humor him, he may have something useful, after all. Mentally, he was already working out which forms to submit to request the psychiatric assessment.

"Suppose a broker in Columbia wants half a ton of heroin to arrive in upstate New York." Matthias ground his cigarette out in the ashtray, even though it was only half-finished. "He has a choice of distribution channels. He can arrange for an intermediary to buy a fast speedboat, or a light plane, and run the Coast Guard gauntlet in the Caribbean. He can try a false compartment in a truck. Once in the United States, the cargo can be split into shipments and dispatched via other channels-expendable couriers, usually. There is an approximate risk of twenty-five percent associated with this technique. That is, the goods will probably reach the wholesaler-but one time in four, they will not." His face flickered in a fleeting grin. "Alternatively, they can contact the Clan. Who will take a commission of ten percent and guarantee delivery-or return the cost in full."

Huh? Mike sat up slightly. Matthias's habit of breaking off and looking at him expectantly was grating, but he couldn't help responding. Even if this sounded like pure bullshit, there was something compelling about the way Matt clearly believed his story.

"The Clan is a trading consortium operated by the noble houses," Matt explained. "Couriers cross over into this world and collect the cargo, in whatever quantity they can lift-they can only carry whatever they can hold across the gulf between worlds. In the other world, the Clan is invincible. Cargos of heroin or cocaine travel up the coast in wagon trains guarded by the Clan's troops. Local rulers are bribed with penicillin and aluminum tableware and spices for the table. Bandits who can muster no better than crossbows and swords are no match for soldiers with night-vision goggles and automatic weapons. It takes weeks or months, but it's secure-and sooner or later the cargo arrives in a heavily guarded depot in Boston or New York without you ever knowing it's in transit or being able to track it."

There was a click from across the room. Mike looked round. "This is bullshit," complained Pete, stripping off his headphones. He glared at Matt in disgust. "You're wasting our time, do you realize that?" To Mike, "Let's just charge him with trafficking on the basis of what we've already got, then commit him for psych-"

"I don't think so-" Mike began, just as Matthias said something guttural in a foreign language the DEA agent couldn't recognize. "I'm sorry?" he asked.

"I gave you samples," Matt complained. "Why not analyze them?"

"What for?" Mike's eyes narrowed. Something about Matthias scared him, and he didn't like that one little bit. Matt wasn't your usual garden-variety dealer's agent or hit man. There was something else about him, some kind of innate sense of his own superiority, which grated. And that weird accent. As if-"What should we look for?"

"The sample I gave you is of heroin, diacetyl morphine, from poppies grown on an experimental farm established by order of the high Duke Angbard Lofstrom, in the estates of King Henryk of Auswjein, which would be in North Virginia of your United States. There has never been an atomic explosion in the other world. I am informed that a device called a mass spectroscope will be able to confirm to you that the sample is depleted of an iso-, um, isotope of carbon that is created by atomic explosions. This is proof that the sample originated in another world, or was prepared at exceedingly enormous expense to give such an impression, for the mixture of carbon isotopes in this world is different."

"Uh." Pete looked as taken aback as Mike felt. "What? Why haven't you been selling your own here, if you can grow it in this other world?"

"Because it would be obvious where it came from," Matt explained with exaggerated patience. "The entire policy of the Clan for the past hundred and seventy years has been to maintain a shroud of secrecy around itself. Selling drugs that were clearly harvested on another world would not, ah, contribute to this policy."

Mike nodded at Pete. "Switch the goddamn recorder on again." He turned back to Matthias. "Summary. There exists a, a parallel world to our own. This world is not industrialized? No. There is a bunch of merchant princes, a clan, who can travel between there and here. These guys make their money by acting as couriers for high-value assets which can be transported through the other world without risk of interception because they are not recognized as valuable there. Drugs, in short. Matthias has kindly explained that his last heroin sample contains an, um, carbon isotope balance that will demonstrate it must have been grown on another planet. Either that, or somebody is playing implausibly expensive pranks. Memo: get a mass spectroscopy report on the referenced sample. Okay, so that brings me to the next question." He leaned toward Matthias. "Who are you, and how come you know all this?"

Matt extracted another cigarette from the packet and lit it. "I am of the outer families-I cannot world-walk, but must be carried whensoever I should go. I am-was-private secretary to the head of the Clan's security, Duke Lofstrom. I am here because"-he paused for a deep drag on the cigarette-"if I was not here they would execute me. For treason. Is that clear enough?"

"I, uh, think so." Pete had walked round behind Matt and was frantically gesturing at Mike, but Mike ignored him. "Do you have anything else to add?"

"Yes, two things. Firstly, you will find a regular Clan courier on the 14:30 Acela service from Boston to New York. I don't know who they are, so I can't give you a personal description, but standard procedure is that the designated courier arrives at the station no more than five minutes prior to departure. He sits in a reserved seat in carriage B, and he travels with an aluminum Zero-Halliburton roll-on case, model ZR-31. He will be conservatively dressed-the idea is to be mistaken for a lawyer or stockbroker, not a gangster-and will be armed with a Glock G20 pistol. You will know you have arrested a courier if he vanishes when confined in a maximum security cell." He barked a humorless laugh. "Make sure to videotape it."

"You said two things?"

"Yes. Here is the second." Matt reached into his pocket and pulled out a small, silvery metallic cylinder. Mike blinked: on first sight he almost mistook it for a pistol cartridge, but it was solid, with no sign of a percussion cap. And from the way Matt dropped it on the tabletop it looked dense.

"May I?" Mike asked.

Matt waved at it. "Of course."

Mike tried to pick it up-and almost dropped it. The slug was heavy. It felt slightly oily and was pleasantly warm to the touch. "Jesus! What is it?"

"Plutonium. From the Duke's private stockpile." Matt's expression was unreadable as Mike flinched away from the ingot. "Do not take my word for it; analyze it, then come back here to talk to me." He crossed his arms. "I said they were a government. And I can tell you everything you need to know about their nuclear weapons program…"