Episode 1

 Wormwood, who lived in the basement, wouldn't leave when Ellen and I bought the big yellow house.  

"Wormwood" isn't a name which leaves a good first impression, is it? It sounds invasive and toxic.

But Ellen Googled "Wormwood" and discovered that it's the common name for the herb artemisia.  Presumably artemisia is named for Artemis, sacred forest huntress. The herb has antiseptic properties and is used to make absinte.  

The Wormwood I knew was clean but not antiseptic, was held sacred by no one, and would not move out of my house.  

As we'd hoped to do since we'd found out Ellen would be appointed chair of her department, my wife and I purchased the enormous mustard-colored house from Cufton College. The school had acquired Horton House forty years earlier as a bequest after a negative outcome from surgery to remove Margaret Hoople Horton's spleen.

Though flimsy interior walls divided Horton House into three apartments -- two downstairs, one up -- each living area was roomy, with high ceilings and wide multi-paned windows. 

The basement, where Wormwood lived, was roomy but dimly lit.  The narrow gasement  windows, set into the cinderblocks, were dirty rectangles shrouded by half-dead salvia twigs. The ceilings down there were head-smackingly low, but there was plenty of space to move around in. 

On the day that Ellen and I first toured Horton House, Wormwood was down in her basement lair, sleeping under a crocheted orange-and-black afghan.  Personally I found it odd to be shown a home where someone was sleeping on a folding cot, but our real estate agent was Ellen's brother Adam so I kept my own counsel.

On the tour we followed Adam to the stairway where a neon yellow diamond-shaped road sign was nailed to the top of the doorway.  The sign, bordered in black, said "Prepare for Three-Mile Descent."  We thumped down the wooden steps, and at the bottom, Ellen, Adam, and I paused for a moment as our eyes adjusted to the dimness. 

Along the low ceiling, clusters of dusty, riveted heat ducts twined like branches. Directly under the largest duct pipe was a cot, braced by X-shaped wooden legs. On top of the cot was a figure wrapped in a crocheted coverlet. Startled, I looked at Adam but he didn't react.

Ignoring the person on the folding cot, Adam took a penlight from his shirt pocket and said, "Let me show you the furnace." Ellen and I followed her brother past the afghan-wrapped bundle, then past stacks of plastic storage bins, to a behemoth double firebox with metal octopus arms sprouting all over from it.

"They left the coal-burner here when they put in the gas furnace sometime in the fifties," said Adam. "You can see the coal chute back there." The small white circle of his penlight skimmed over a squared-off metal extension. This ran down from  a rusty, hinged door in the cinderblock foundation wall. The open chute slanted further down to a spot about a foot above the basement floor. The concrete still showed black sooty dust in its crevices. 

"They had a coal bin there at one time," Adam said, "but that's been taken out." The small circle of light returned to the furnace. "This boiler's had a safety valve put on right here --" He reached out with the slim silver flashlight and tapped the electrical box bolted onto the furnace's side panel "-- because no one wanted the boiler to run dry and go blooey."

"How exactly does the safety device work?" I asked.

"Sensor in there," said Adam. "Water sensor. If the level goes down to a certain point, a relay shuts the furnace off." He clicked the penlight and the small white circle disappeared. 

We passed back through the basement on our way to the wooden steps, and I noted that the folding cot now had only the crumpled afghan on it. Was the person now loose upstairs, ready to confront us in some doorway?