He knows the entire place has eyes. Not just from Albus, but the building itself. So he keeps it hidden in the very earth, where the stones cannot sense its presence. He doesn't hide it with magic, because magic can be sensed out, found. It would make it obvious that he is hiding something. So its resting place is under the loose stones that can be pulled up to reveal the hole he dug. Sometimes, when he's sure no one is looking, he takes out the box. All the remnants of his past life (the one he wants to think about) are in it. All of his shame and joy. He gently removes the folded robes, black like the deepest ocean waters, black like the end of the world. The material is rough like burlap, rough like the shattered bricks of a collapsed building, rough like the fragments of bone left from their victims. Sometimes he thinks it should drip too, drip with the blood of every life they so carelessly snuffed out. He takes out the mask now, smooth like an opal but so much uglier. It's bleach bone white. Someone has taken the time to strip the flesh and wash what's under, to lovingly display their work.
"This is your heritage, Tommy," he says to his son. Tommy squirms on his lap like any two year old would, fist in his mouth and black eyes wide in the dim light. He's not sure why he's showing him these things. Maybe to prove to him(self) that his father(husband) was a great man or a horrible man. Sometimes he wonders which. Tommy's tiny fist wraps around the black of the robe, new and fragile fingers clutching at the fabric, trying to decide what it is and if it's worth his time. He does the same with the mask, this item he puts in his mouth, trying to chew on the edges. Gently he unwraps the baby's fist, pulls the mask from his delicate mouth. "No Tommy." But he's not surprised. He always suspected that Tommy would be fond of these things. He sees so much of Tom in their son, even at so young an age. He sets his garb to the side, and pulls out the only other treasure the trunk has to offer.
It's a photo album with only five pictures in it. He's not sure if Tommy should see these now when he's too young to understand, or see them when he's older and be able to grasp the gravity of them. So he'll show him now, when he doesn't have to worry about Tom's influence, doesn't have to worry about an unhealthy love of torture or bitter anger at the loss of his father. He opens the album then and takes out a photo. This first one is of their wedding, but it looks more like a funeral. He hadn't been interested in a wedding, but Tom had insisted. Tradition was important, solemn and somber were the sort of things Tom liked. In the middle of the frame they stood next to each other, not kissing, not smiling, not even touching. Tom wore black because Tom always wore black. He himself wore a deep, mossy green. All around them in a circle were Tom's followers, faces hidden in their masks. He didn't think a picture existed where they didn't have their cloaks and masks. They were too proud of their atrocities, yet too afraid to show their real faces. But he hadn't known that at the time.
The next photo was of himself, heavily pregnant, stretched out on a couch in his dressing gown, reading a book and smoking a cigarette. He used to go through a pack and a half a day. The stress of being pregnant and a murderer was… taxing. He could still taste the must on his tongue sometimes, still itched to hold something to his lips. Tom had made him quit, for Tommy's sake. He couldn't begrudge him that. He hadn't taken up the habit again after Tom was gone, though working at a boarding school probably had something to do with it as well.
This photo was of him holding Tommy right after he was born. It had been a surprisingly easy birth, all things considered. Which was lucky because it as if they could go to a hospital, being wanted criminals and all. Tom had stood with him the entire time, silent but encouraging simply by being there. It hadn't been proper for fathers to watch the birth at that time, but no one would dare question Tom about his methods. For all of his flaws, he was a loving man, if in his own way.
The photo after was of all of them. He was holding a squirming, six month old Tommy with a smiling face. Tom had his arm around his waist, and in the tiny moving picture he would lean over to smile and have a closer look at their son. He himself had taken to parenthood much easier than he had thought. He had patients where it counted, and would gently guide his infant son. If anything, he was the more stern of the two parents. Tom was much more indulgent in Tommy's whims. When he was a year old he would set the boy on his lap and read him texts of dark arts, grimoires, and fairy tales. "Indoctrinate them early. I must teach my boy proper values, my dear," he had said with his sweetest voice. Tom knew he thought Tommy was much too young for some of it. Surely it was good to get a head start on education (no son of his would be a simpleton), but Tom always seemed to take things just a step too far. "This is the spell that turns someone inside out," he said, pointing to an illustration of bones and organs flying out of a man's mouth while his skin and hair went sucking in. Tommy regarded it with graphite eyes, his mother's own, with a strange intensity. Tom smiled when little Tommy grabbed for the book with his chubby baby fingers.
The last picture he had of them was one he felt he ought to burn, but just couldn't bring himself to do it. He had so few mementos from their brief time together so he clung to every one, even the ones that showed the darker side of his life. They were in the hall Tom used to gather his followers, sitting in roughly hewn wooden thrones. Tom's was slightly taller; he wanted them all to know he was the leader of their organization. He was their king, their god. But his spouse was still nothing to scoff at, still demanded their begrudging allegiance. Severus had enjoyed watching them bow before him. For the first time he had power, he had respect, he had a true family. In the little picture they sat in their respective thrones, faces bare and proud before the ring of their masked, faith(less)full followers. Tommy was on his father's lap in this one, just one year old. Tom had been proudly showing his son, his heir, to his apostles. Tommy was a lovely baby. He would wear his father's handsome face someday, but with his mother's eyes.