The opening was barely twenty inches across. An upright square cut into the vaulted ceiling of the old storm under-road drain. Len lowered a hooded copper lantern on a braided lanyard. He watched the yellow beam swing across glistening, black surfaces five feet below. What should have been an open stone drain was almost entirely filled by a massive, interwoven web of woody taproots and stringy rhizomes.
Over twelve years of artificial warmth and nonstop moisture, the roots of the surface groves had sought the sulfur-rich runoff. That forced their way between the mortar joints of the vaulting until they formed a solid plug of living wood that choked the passage like a jammed raft in a millrace. The stone stonework around the shaft was blackened by hundreds of years of damp, coated in a thick, velvety layer of slime that smelled of stale river mud and decomposing leaves.
The air rising from the hole carried a sickening chill that hit Len’s face like wet felt. It was an ancient, stale cold, fully divorced from the engineered climate of the greenhouse above. Up here, under the low stone arches, the air had been warmed by copper steam radiators and coal stoves. It smelled of rich compost, drying herbs, and citrus boughs. Down in the under-road drain, there was only the smell of stone decay, rotting vegetation. The faint, sweetish stench of trapped marsh gas that made the eyes sting behind their sockets.
