Doggo:

"Hey, Sans…" Undyne attempted softly, shaking his shoulder lightly - like it would help anything. Doggo's aloof attitude waned a little, guilt became more obvious in the sentry's shifty eyes through the glassy material of his glasses. His eyes wandered, taking in the reserved skeleton's home. It was clear that it had not been cleaned for months, dust coated the furniture and the corners of the floor. But it was also apparent the house hadn't been dirtied either, everything was left mostly untouched.

Doggo's eyes narrowed sadly, the house seemed so empty, so lonely, so big Sans didn't know what to do with it.

Undyne picked him up gently, guiding him over to his couch, laying him on it with a flurry of complaints from the crummy dust-seat. Doggo wanted a smoke. Sans hated to show weakness, He hadn't even let Papyrus pick him up like that. Undyne joined him, sitting down with another more violent protest from the couch. She was shaking him, murmuring for him to wake up. He could tell the captain was spooked. She had only ever been this gentle when guards were seriously wounded in training accidents, or when monsters had fallen down.

Doggo left her to it, wrinkling his nose as he passed the kitchen on his way up the stairs. Something smelt god-awful over there, no way he was setting paw near. He was planning to grab Sans a pillow or something - he didn't look like he was going to wake up soon -, but something else caught his eye as he entered the hallway. The bathroom door was open wide, a light flickering dimly from the room and filtering through the hall. He poked his snout in, sniffing madly at the slight smell of hospital. It was coming from a woven basket, leaning halfway out of a built-in cabinet on the wall. The thing had been ravaged, its contents were spilling out onto the tile. The primary being medical supplies, but there were miscellaneous rags and soap packets sprinkled in too. One of the liquid medicines had been cracked, a thick pink substance oozing from it and onto the floor. That accounted for the smell of hospital. Or perhaps plastic. The two were both sweet or clean scented in nature. But in his experience it was too clean, to the point of smelling saccharine, like it was covering a stench that must have been far worse.

What was most troubling was the trail of pills billowing out of a lone container like a river, spread out across the floor haphazardly. He picked up the container, examining the label. Some sort of pain relief, they were scattered all over the floor…

A horrifying thought crossed his mind. Sans couldn't have…?

Doggo heard talking downstairs, his ears perking up. He set the bottle down, apologizing under his breath as he trespassed Sans's room to grab the pillow he had come for. When he returned downstairs Undyne was shaking Sans again, but his eye sockets were drooping, blinking in confusion when Undyne refused to let him rest.

Doggo neared, lingering a few paces back from the couch. He really hadn't meant to invade Sans's home like that, he'd only come because Undyne had guilt-tripped him. Doggo had always been one to reckon that one's business is their business alone. And he firmly believed everyone deserved to be respected in that regard, a person's pride is theirs to relinquish, and nobody else's. -But then again, if they hadn't checked on him, would he have stayed collapsed on the stairs for possible days?

If so, would anyone have ever bothered to find out what was causing the skeleton sentry's absence?

Doggo didn't want to think about it.