Did you figure it out? If not, or just to make sure, here is how the mystery comes together. The important thing to keep in mind is that not every mystery can be solved by a simple process of elimination: excluding one suspect after another until there is only one left. And though most murders are committed by someone who has a strong relationship or connection to the victim, this doesn’t always have to be the case. If the motive is financial gain, it is quite possible that the link between killer and victim is only slight–if at all!

The suspects in this case all have some connection with the late Oliver Foggleton, and/or maybe some connection with the victim, Foggleton’s ex-wife, Marisa Hightower. Remember, the death of Foggleton is relevant only with respect to the eight beneficiaries of his will (the housekeeper Katie Winterthorpe included, but not considered a suspect). Melissa Hightower was to receive the land and the castle; with her death, according to the stipulations of the will, the estate was to be distributed evenly among the six suspects. So to begin, we need to start with our MMO: Means, Motive and Opportunity.

“Means” means the access to whatever it took to cause Marisa Hightower’s death. In this case, poison. Foggleton’s protégé Robert Vogel was the only one who had a police record involving poison—that is to say, drugs—but according to that police report, we know that the poison used was a common recreational drug in San Francisco, to which everyone would have had easy access. Especially in the arts world. Singling out Vogel would be like arresting only the butcher in a stabbing investigation, even though all the other suspects have the same knife in their kitchen drawer. Mind you, we’re not saying he’s innocent, only that all the suspects had the means to obtain the murder weapon.

“Motive” is where things get a little more personal. Sure, there were arguments over time between Marisa Hightower and some (not even all) of the suspects, but nothing that endured or would seem a likely motive for murder at this particular time. Revenge? Jealousy? Not likely. Murder for love, thrill or “concealment” (that’s when a person murders to cover up another crime)? There’s no evidence for any of those. Keep in mind that all the suspects are just that—suspects—because they, and only they, have one thing in common: The death of Marisa Hightower provides them with substantial financial gain.

Even though all the suspects get to choose objects of considerable value from the estate of Oliver Foggleton, they all become considerably richer if they also get to divide the house and property five ways, if the beneficiary of said house and property is not available to claim her inheritance. Much richer: The property has been estimated at £1.8 million (a whopping 2,497,000 in dollars, give or take a few hundred thousand), and Saundersfoot Castle alone is worth up to an estimated £480,000 (that’s $666,000). Calculating in dollars—the currency all our suspects use—we get $2,497,000 + $666,000 = $3,163,000, divided by six, equals $527,167, or over half a million dollars additional for each. People have killed for a lot less than that. The motive, quite simply: greed. Whoever killed Marisa Hightower knew he or she stood to gain an additional half a million; it didn’t matter that others benefitted as well.

Now it really gets difficult. If everybody stands to gain so much and so equally from the death of Marisa Hightower, and there doesn’t appear to be any motive besides greed—nothing personal between any of the suspects and the victim—then every suspect is subject to the same suspicions. That brings us to “Opportunity.” Timewise, no one person had a better opportunity than anyone else to murder Ms. Hightower before that fateful plane trip, since one-on-one contact with her was always limited and anyone doing her harm when they were alone together would have no other suspects to deflect the accusing eyes. On the plane, however, every suspect had the same access to Marisa Hightower’s drink, to pour in a few drops of poison when no one was looking, and the killer would blend right in, looking no more suspicious than any other suspect.

But the key is not the drops of poison added to the drink, it is the poison used to line the glass before the drink was poured. Consider the forensic report. Two things stand out. First, poison was not only found in the little bit of liquid at the bottom of the glass, it was also lining the glass in some sort of clear gelatin. Secondly, the only fingerprints found on the glass were those of the victim, Marisa Hightower herself. It would not have been particularly easy for someone to handle the glass, drop the poison in it, and then wipe off all fingerprints before setting the glass back on the victim’s tray table without being seen. The glass had to have been prepared in advance, and then, for good measure, drops of poison were added to the poison-lined liquid-filled glass.

You can see it now, right? The flight attendant, Constance Laughlin, had the opportunity to prepare the poison-filled glass ahead of time. Her mistake (besides being too greedy) was in wiping off her fingerprints before she served the glass to Ms. Hightower, thinking she was removing evidence of her involvement, when, in fact, her fingerprints should have been on the glass, as would be expected, since she was the server. Instead, she put a glass with no fingerprints on it onto a tray, which the victim then removed from the tray, applying only her fingerprints to the glass.

Like all the other suspects, Constance Laughlin knew about Oliver Foggleton’s will and its stipulations. The only difference was that flight attendant Constance Laughlin murdered a person she had never met outside an airplane just to greatly increase her shared inheritance. She assumed she would be no more of a suspect than any of the other beneficiaries, especially since everyone benefitted equally. Maybe she didn’t mean to kill Marisa Hightower, since all the flight attendant needed to do was keep Ms. Hightower from reaching Saundersfoot Castle. Even if the victim had not died, according to the stipulation in the will requiring that all beneficiaries be present in Saundersfoot Castle at the given time, Marisa Hightower’s absence, no matter what the cause, would mean that she would legally forfeit any rights to the castle and property.

Constance Laughlin whimpered when arrested by San Francisco police at her apartment, and kept repeating, “I didn’t mean to kill her! I just wanted to keep her from getting to the castle!” Because she had no previous record, and the intent to cause death would be hard to prove, she was offered—and accepted—a plea of second-degree murder. Constance Laughlin is now serving a 15-year sentence (U.S. Sentencing Guidelines, level 36) in the California Department of Corrections and Rehabilitation on Mission Street in San Francisco, not far from the community in which she was well known and well liked.