One of the difficulties with a setting as unique as Trail of Cthulhu is that some of the terms are going to be so unfamiliar as to deserve an in-depth explanation. Yet there's only so much space in the book, and some things are bound to be truncated to make room for other, more important elements. One such is the Ring, described as a cabal of book-buyers whose cooperation allows them to pull off the Knock; to cheat by agreeing to gang up on the competition, knocking them out early so that members of the Ring can then pick up the good stuff at bargain prices.
There's a story in Dorothy Sayers' collection of short stories, Lord Peter Views the Body, that features the Ring in all its glory. The tale is The Stolen Stomach and its hero, amateur sleuth Lord Peter Wimsey, is helping a friend in Scotland. However there happens to be an auction in London that Lord Peter is particularly anxious to attend, so rather than immediately dash off to the Highlands he sends a telegram and then goes off to the auction, with the result that he's not on-hand to deal with the problem in Scotland at a critical moment. Sayers describes the auction in some detail, which I will quote here:
[Lord Peter] had great fun at the sale the next day. He found a ring of dealers in possession, happily engaged in conducting a knock-out. Having lain low for an hour in a retired position behind a large piece of statuary, he emerged, just as the hammer was falling upon the Catullus for a price representing the tenth part of its value, with an overbid so large, prompt and sonorous that the ring gasped with a sense of outrage. Skrymes - a dealer who had sworn eternal enmity to Wimsey, on account of a previous little encounter over a Justinian - pulled himself together and offered a fifty-pound advance. Wimsey promptly doubled his bid. Skrymes overbid him fifty again. Wimsey instantly jumped another hundred, in the tones of a man prepared to go on till Doomsday. Skrymes scowled and was silent. Someone raised it fifty more; Wimsey made it guineas and the hammer fell. Encouraged by his success, Wimsey, feeling that his hand was in, romped happily into the bidding for the next lot, a Hypernotomachia which he already possessed, and for which he felt no desire whatever. Skrymes, annoyed by his defeat, set his teeth, determining that, if Wimsey was in the bidding mood, he should pay through the nose for his rashness. Wimsey, entering into the spirit of the thing, skied the bidding with enthusiasm. The dealers, knowing his reputation as a collector, and fancying that there must be some special excellence about the book which they had failed to observe, joined in whole-heartedly, and the fun became fast and furious. Eventually they all dropped out again, leaving Skrymes and Wimsey in together. At which point Wimsey, observing a note of hesitation in the dealer's voice, neatly extricated himself and left Mr Skrymes with the baby. After this disaster, the ring became sulky and demoralized and refused to bid at all, and a timid little outsider, suddenly flinging himself into the arena, became the owner of a fine fourteenth-century missal at bargain price. Crimson with exitement and surprise, he paid for his purchase and ran out of the room like a rabbit, hugging his missal as though he expected to have it snatched from him. Wimsey thereupon set himself seriously to acquire a few fine early printed books, and, having accomplished this, retired, covered with laurels and hatred.
Clearly Sayers knew a great deal about auctions, which given her academic interests is not surprising, but there are several elements here which will be useful to Bookhounds.
First, it makes clear that the Auction ability has little - if anything - to do with money. This is a mental trap that even my own players sometimes fall into, thinking that the person with the most money always wins. The above extract makes it clear that a bidding war is more about intimidation, psychology and deceit than it is about cash. You know how to handle yourself in an auction is the very first line of the ability description, and at no point does it even mention cash.
Second, it's a reminder that other abilities will come in handy in an auction setting. Clearly Lord Peter doesn't depend on his Auction score; either Stealth, Disguise or Conceal could cover the incident with the large piece of statuary, a fair amount of Intimidation was going on, and Sense Trouble could account for the a note of hesitation in the dealer's voice which tells Lord Peter that the time has come to jump ship.
Third, it's a pretty clear indication that the Ring isn't just a shadowy cabal, but made up of people with their own goals and desires. If Skrymes had kept his head he and his partners might have carried off the knock even with Lord Peter's interference, but because he didn't the whole thing fell flat. Once Skrymes had been dealt with the Ring lost all hope, and Lord Peter was able to do as he pleased; even the little rabbit got away with his missal.
To begin at the beginning: a Ring is an informal term for a collection of people acting together to fix the bidding. In its simplest form, members of the Ring viciously go after anyone not in the group while refusing to compete against Ring members. This keeps outsiders intimidated, and allows the Ring to pick up what it pleases at bargain rates. Members of the Ring are usually dealers who want to sell on their purchases for a profit, so the cheaper they can get their merchandise the better they like it.
However that isn't the only thing a Ring can do. Where the owner of the item being auctioned is a member of the Ring, one possible cheat is to bid up the article in question and then drop out once other bidders have joined in. That pumps up the initial price, which in turn means that the item's owner will probably walk away with more than he would otherwise have done. This is particularly likely to happen where the Ring is made up, not of dealers, but of owners; it may also happen that the Ring is made up of people trying to pass off fake goods, upping the bidding to make the item seem worth more than it actually is. Remember the auctioneers in the above description, who fancied that there must be some special excellence about the book which they had failed to observe. People in the auction room simply don't know what an item really is worth, and they can be persuaded - through psychological manipulation - that the stuff they're dealing with is worth much more, or much less, than it actually is. They're guessing, and so they can be bullied or tricked into guessing incorrectly.
It's all about psychology and intimidation, as anyone who's ever watched Storage Wars will know. That A&E show features a regular character, Dave Hester, whose 'YUUUUP' catchphrase is his trademark. Yes, it's about being heard, but it's also about letting the competition know who they're dealing with; not unlike Lord Peter's tones of a man prepared to go on till Doomsday. Money is certainly part of the equation, but in many ways its the least part of it; a flashy roll attracts the eye and makes the competition think twice, but whether it's all bills or bills plus newspaper clippings is impossible to tell at a glance.
In game terms, a Ring is clearly Cooperating, as described on page 58 of the main book. Several people pool their Auction scores together in order to achieve a common goal, which means that for purposes of gameplay the Ring's Auction ability is going to be very high. The Keeper should consider either designing several different cabal members, so that each has an individual Auction pool, or assigning a joint Auction pool for the group. That pool is going to be fairly high, whichever route the Keeper goes; scores of 15+ should be common for a Ring.
That probably puts them in a power position when dealing with an individual player character, but it doesn't have to stay that way. Intimidation can shave a few points off that total, and the players will probably come up with other ways to bluff the Ring into losing even more from their pool. Moreover as Skrymes shows individual Ring members can be split off from the pack - another reason for designing individual Ring members rather than assigning a pool - and defeating one of these on their own could be enough to break the Ring altogether. Remember, these aren't shadowy criminal masterminds; they're just bidders who happen to have formed a temporary alliance, perhaps over tea that morning. They don't have hordes of minions to do their every bidding; at best they may have suborned the auctioneer, or someone else working for the auction house, but dacoit assassins are well beyond their remit.
That said, they might know people who know people. Strong-arm men, forgers, burglars and con artists are just the sort of shady characters members of a Ring might know. In theory someone desperate to get their own back on an interfering player character could call on these resources, if they really wanted to. Again, this doesn't mean hordes of minions to fling into combat; at best it's two blokes willing to rough someone up in a back alley. Still, it's better than nothing, and a likely consequence of offending someone with shady friends.
One final word for the Keeper: remember that bidding in an auction has nothing - or very little - to do with money. It's about power, and who has it, which is why the Ring does very well for itself. They know the importance of power, and are willing to cooperate - temporarily at least - to achieve a common goal. If the player character wants to go up against the Ring he'd better be very sure of himself, otherwise he could be left - like Skrymes - holding the baby.