A few months back, I brought my little sister, Ava, into our home. She was only eighteen, still frail from battling a severe condition that had knocked her out of high school for nearly a year. I thought having her close would be good for her health, until I noticed something strange about her behavior.

The treatments Ava underwent were long and grueling, but she came out on the other side—scarred, sure, but standing. My wife, Dana, seemed on board when I first brought up having my sister live with us.

She smiled, said it was a good idea. Ava’s doctors were in our state, while our parents lived all the way out in Ohio. My sister still lived with them permanently, but I figured the best thing was to let her rest and recover in a familiar place while still having quick access to her doctors.

Ava also had a few friends in the state I lived in, and I thought staying with us would help her slowly ease back into social life. I hoped being with us would give her a sense of comfort and help her heal quicker.

At first, it felt right, and she seemed okay being here. My sister was quiet, but not withdrawn. She eventually started going out for walks, met up with some old friends a couple of times, even smiled at dinner now and then. But after a few weeks, she changed.

Ava stopped going out, wouldn’t even take the dog for a walk—and she adored him. She stopped spending money on her art supplies, which had always been her therapy, or anything for herself. Every time I passed her room, I’d hear nothing.

Just silence. Curtains drawn. Lights off. Sometimes I’d catch her sitting on the edge of her bed, just staring at the floor. She barely left her room, and I was seriously worried that something was wrong with her health and she wasn’t talking about it.

I gave it time. I figured maybe the post-recovery depression was kicking in. But eventually, I couldn’t ignore it anymore.

One morning, while my wife was out, I tapped on my sister’s door.