it.

The asteroid was a quarter of a mile away, seen through the infra-red.
The dome loomed large.

"All right!" whispered Hawk Carse. "Hold on!"

With the words he unleashed the _Sandra's_ full acceleration.

* * * * *

It was a risk and a big one, but the Hawk had it calculated to a
fraction of a second, and so, without hesitation, he took the chance.
A little less than four seconds to reach his objective, he reckoned; a
little more than one second for Tantril to release the asteroid's
disintegrating rays as he had threatened; therefore about two and a
half seconds for the _Sandra_ to be exposed to those rays. The chance
that her defensive web could resist them for that long would decide
it.

From almost a standing start, the _Sandra_ swept ahead, generators
humming, her web a blue mist around her, acceleration at the full.
Straight down through the heart of the narrowing purple ray she sped,
a hurtling metallic projectile, hundreds of tons in mass, her stub bow
levelled dead at the dome.

After a second the asteroid bared its fangs.

A cone of brilliant orange flamed and washed around the _Sandra's_
bow, and a storm of soundless sparks engulfed her. She was caught in a
maw of fire, and held there for the remaining terrific seconds of her
wild forward dash. But the seconds passed; the hands of Hawk Carse
were delicate on her controls; and the _Sandra_, curving slightly
upward, struck, crashed, wrenched terribly in every joint; and then
the jolt and the protesting wrench and the spluttering sparks were
gone from her, and there was around her only the deep silence of
lifeless space.

At three hundred miles an hour the _Sandra_ had nicked the upper
plates of the dome and streaked on, unharmed!

It was not necessary now to use infra-red glasses to see the asteroid.
It was there in the visi-screen for naked eyes, but for seconds not
one of the men in the ship's control-cabin thought to look. The awful
acceleration and shock had dazed them. They had not known what was
coming, except Friday and the Hawk, and only the latter was able to
retain reasonable alertness. He, almost immediately after the impact,
cut down the load on the generators, and brought the _Sandra_ out of
her mad drive forward, rotating the ship until she was facing back
towards the asteroid. Then all of them looked through the bow windows,
and what they saw told the story in an instant.

"It's visible! See--the