Foster smiled grimly. "The trail has brought us here. We must follow it—wherever it leads."

I lay on the ground, staring up at the unbelievable shape across the field, the beckoning square of light. "This ship—or whatever it is," I said; "it drops down out of nowhere and opens its doors. And you want to walk right into the cosy interior."

"Listen!" Foster cut in.

I heard a low rumbling then, a sound that rolled ominously, like distant guns.

"More ships—" I started.

"Jet aircraft," Foster said. "From the bases in East Anglia probably. Of course, they'll have tracked our ship in—"

"That's all for me," I yelled, getting to my feet. "The secret's out—"

"Get down, Legion," Foster shouted. The engines were a blanketing roar now.

"What for? They—"

Two long lines of fire traced themselves across the sky, curving down—