Mary tried to imagine the day of Amadeo’s death. The rope tying him to the tree, coming undone. Amadeo falling to the ground. The horror of the friend when he woke up, unable to call anyone to help. Not that anyone could have helped anyway. Mary had worked on enough murder cases to know a little about strangulation. The rope would have ruptured the carotid and other vessels in Amadeo’s neck, and he would have bled to death, internally, over a period of hours. He would have known that he was dying. Would that have made him happy? Finally given him peace, knowing that he would join Theresa? Mary couldn’t help but shudder at the thought. Even in her grief over Mike, she had never considered suicide. Her parents would have killed her.

Part of her wished Mr. Milton hadn’t told her the truth, because it hurt to think of Amadeo suffering. She tried to dismiss the thought but couldn’t. She sighed, needing suddenly to lie down. She took off her blazer, folded it in half, and laid it flat on the other bed, near the glass sliders. Outside, the father was bending over the little boy, evidently instructing him as he tied something to the end of his fishing line. A lure, she guessed, or a fly of some kind. Last night there had been people fishing in the same spot, not fifty yards from the Doubletree. Mary knew that fly-fishing was big in Montana, from a movie she’d seen on Encore with Brad Pitt. Broad Street Runs Through It.

She kicked off her loafers, went back to bed, and sat down, bending over and pulling off one nylon knee-high, then the next. Nobody else at Rosato bothered with nylon knee-highs, but Mary had grown up watching the mamarellas on the C bus wear them with dresses and had nursed a secret fondness for their taupe ugliness. She was about to drop the mamarella socks on the floor and lie down, but she looked at them again. They were the cheap kind from the Acme and had shriveled to nothing without her calf to give them shape. In fact, they looked like two pieces of brown rope.

Just then Mary heard an excited yelp from outside her window and looked up. The little boy’s fishing rod had bent almost to breaking, and he was reeling something in, braced against the strain and the moving water. His father held on to him with a sure hand. In the next instant, a fish shimmering with color and water burst from the river into the air, its long body torquing before it fell sideways into the river, with a splash.

Mary watched, transfixed; the fish was a strong, wild animal, fighting for its life, which is not the kind of thing you see at Tenth amp; Ritner. The boy cranked his reel, the father held on tight, and the trout jumped from the river again, thrashing more weakly. It happened one more time, the boy and the fish locked in a lethal battle that the boy eventually won, reeling in the fish close enough for his father to scoop it into the net. The boy jumped with glee, and the father gave him a hug. Then they bent together over the fish, and the father reached into the net. After a minute, they let the fish swim away.

Mary smiled at the happy ending. She had no idea that a fish could be so big or so powerful; they were so calm in the Chicken of the Sea can. Whatever the boy had tied on his fishing line had done the trick, and the line itself had to have been strong. She considered it. Fishermen had to know how to tie things onto other things. Knots were something that fishermen knew about. Even a city girl like Mary had heard the term fisherman’s knot.

On impulse she went with the mamarella socks to the borrowed laptop she’d set up on the desk, then hit the enter key to wake it up. She logged onto Google, typed in “fisherman’s knot,” and the cheery blue-and-white screen yielded the results of her search. She eliminated the first few links, which looked irrelevant, then about the middle of the page came upon what she was looking for: Get Knotted! Animated Knots for Scouts! She clicked on the link, and the screen changed as the computer found the website, which was for a Boy Scout troop in East Sussex, in the United Kingdom. Underneath the title was a bright blue list of all sorts of knots: bowline, clove hitch, figure-of-eight knot, fisherman’s knot.

Bingo! Mary stopped there and clicked. Fisherman’s Knot, read the heading of the new page, next to a definition:

The Fisherman’s knot is used to tie two ropes of equal thickness together. It is a useful and common knot used by fishermen to join fishing line, and is very effective with diameter strings and twines.

Instantly, at the top of the page, two animated pieces of rope, one bright red and one bright blue, started tying themselves into a very solid knot. She watched the rope tie and untie itself a few times, slowly enough so that even a Philadelphia lawyer could follow. She scanned the page and underneath were directions: Tie a thumb knot in the running end of the first rope – and Mary had to click on a link to learn about the thumb knot part – then tie a thumb knot in the second rope, around the first rope. Note the thumb knots are tied such that they lie snugly against each other when standing ends are pulled.

Mary double-checked the directions, picked up the mamarella socks from the desk, and followed the directions for the fisherman’s knot to tie them together. Then she pulled the reinforced toe of each sock. Presto! She had joined her mamarella socks! She yanked hard. Nothing would make them come apart. She was screwed if she needed to wear them, but she had taught herself one thing. No rope joined by a fisherman’s knot would ever come apart.

What had Mr. Milton said on the phone? Problem was, he made the rope by tyin’ two ropes together… The rope broke where he tied it.

Mary felt a bolt of excitement that was almost electric. The knot in the rope hadn’t held. Amadeo, a fisherman by profession, would have known how to tie a fisherman’s knot. So only one conclusion followed logically, and to confirm it, she didn’t need a ghost. Amadeo hadn’t tied that knot. Somebody else had, and there was only one other man with him in the beet field that day.

Mary reached for the phone.

“It’s almost closing time,” said the cashier at the Fort Missoula museum. It was the same woman in the denim shift, who had helped earlier today and was undoubtedly regretting it now. Mary was on a new mission, to find a mystery man.

“I know, and I’m sorry.” Sorry, sorry, so very sorry. They were upstairs at the museum, and on the way over, Mary had called Frank Cavuto and Jim MacIntire again and left more messages. Skinny Uncle Joey wasn’t in either, and it gave her a pang of homesickness she was too old for. She considered calling home and asking her mother why she was so frigging thin, but stopped because she’d have to reveal she was on Pluto.

“I do have some paperwork to finish up, but then I’ll have to get home.” The cashier hustled down the hall on the museum’s second floor, past the administrative offices, and halted at a door bearing a red sign that read: STOP! YOU ARE ENTERING A CURATORIAL ZONE! “Can you be done in an hour, Mary?”

“If I can’t, I’ll come back tomorrow, if that’s okay with you.”

“Certainly. The director said to help you in any way we can.” The cashier nodded. “What you’re looking for might be in here. If it isn’t, the U has a lot of archival information in the Mansfield Library, as you know.”

“Yes, thanks.” Mary had read as much, and was a library fan from way back. She would never have learned to love books if not for the Free Library of Philadelphia. She’d grown up in a household where there was only one book other than the Bible. TV Guide.

“Our archive is more specialized, as you’ll see. It pertains strictly to goings-on and internees at Fort Missoula, during the internment.” The cashier opened the door with a jingling set of keys and flicked on the light in the small, windowless room, which was wall-to-wall history.