Consulting sober companion, that's what she'd call it. She had a grace period while Holmes recovered from his behavioral relapse and would be less likely to think of asking for details of her alleged extension. Behavioral relapse, right. The clinical phrase didn't quite capture the maelstrom force of his terrible icy determination. Dry drunk didn't even begin to describe it. He'd referred to the rabbit hole of his psyche before, but this was a vortex, an abyss that might — would — reopen without warning.

A few days, then, until he figured out that she'd lied, maybe? Already he seemed to have regained an even keel. She sighed. No. He'd regained the crutch that had been yanked out from under him by Moran's tale. The name written on the card on the wall was keeping him upright now, and it would lead him back down again. Extending her stay might be clinically prescribed under the circumstances but was also ethically murky and unquestionably enabling this addiction. They were more alike than she ever would have imagined. She was doing the wrong thing. She was going to keep doing it.

She knew he would not argue when she pointed out what he was doing with his investigation. He would acknowledge that his actions fit the profile of a user, and he would continue to "use" as long as the drug was out there. Based on his transformation over the preceding five weeks, she knew, she hoped that if Moriarty were ever killed, Holmes could recover. The trigger was specific to avenging Irene. She had to stop herself from judging him for it a little, letting the loss of a woman whom he'd known such a short time obliterate everything else in his life. (What a hypocrite she was.) He was so immature in some ways, so young. Seven months into his first love, at forty. He knew so much and so little.

What was that look he gave her when she said he'd been in love? Indignation that she had dared to label it? That the term was insufficient? Inaccurate? Beside the point? Something was not right there. "Love" apparently was not what he would have called it. And had not, in fact, ever done. "Close" and "smitten" was what he had said. He'd looked almost horrified to hear "love" assigned to what he was describing. She suddenly wondered what Irene would have called it.

Over the next few days he followed her to extra meetings where he sat quietly, looking down at his hands, refraining from both from snark and self-hypnosis. If it were anyone else she'd call it daydreaming. With him, she wasn't sure. Rebuilding his attic, perhaps, after the roof had been blown off.

There was some paperwork to fill out at the station, but they didn't see Gregson or Bell and nobody called. When he wasn't staring at the card on the wall, he picked locks and put away his "security measures," this time pointing out some of the cameras she'd missed and making no more attempt to dissemble about the weapons cached everywhere then he had when he'd retrieved them in front of her.

One night at 3 a.m. she woke up thinking she could hear water running and found him working through the mound of dirty dishes in the sink.

"What brought this on?" she asked. "I don't think I've ever seen you do more than a cursory rinse before."

"It was too cold on the roof. I thought I'd test the hypothesis that dishwashing can promote calmness of mind."

"You can't sleep?"

"The results are inconclusive. You interrupted the experiment, but I doubt it would be worth testing again."

She didn't come down until almost 11 the next morning, and he glanced up at her from the floor where he sat surrounded by paper, raising his eyebrows with his "love your job, hmm?" smirk and saying nothing. He had pulled some boxes out of the VCR closet and appeared to be resorting the contents. Back to normal, apparently. She looked at the boxes and and then slowly turned around, walking into the front room, looking over the shelves and tables and objects and detritus that covered every surface.

She paused by the desk where her phone charged and started shifting papers around, flipping through one disheveled stack after another.

"You knew M would be here," she said, turning around to face him. "That's why you came to New York. Months before Hemdale. You were following him." He looked up at her, scowling and silent. "The trail went cold in London and somehow you figured out he came here or would come here. You didn't bottom out there first; that happened here. You didn't run away because she died. You've been working on this the whole time."

He just glared at her. It was four days since Moran, and there was still nothing else on the wall around the Moriarty card. She sat down abruptly, bending over, hands pressed to her face. "I don't know what to do."

"What?" His voice was harsh.

She sat up and looked at him across the length of the two rooms. "What do you do when you've exhausted all avenues to collect data and still don't have enough information to go on?"

His eyes narrowed as he leaned back away from her. When a minute passed and she didn't say any more, he straightened slightly, warily.

"When I am stymied by a problem I find movement can be conducive to flushing the elusive solution," he said.

"Movement."

"Yes. A walk. Or a jog, you're so fond of. Studies have shown — "

"Fine. I'll get out of here, leave you alone. At least I know there's a good chance you won't disappear on me while I'm out. Right? You think he'll be staying. In New York."

He looked away at the fireplace below the card, scowling again. The dark carved hearth screen showed a large insect flying over thick tangled vines. She used to think it was beautiful.

"I'm not going anywhere," he said.