day, the course trace built up, the cameras recorded the terrain
under the ship, and the two guardsmen built up their mosaic. The ship
crossed and re-crossed the continent, mapping as it went.

From time to time, Lanko made careful comparison of the new mosaic with
an earlier survey, noting differences. There were new settlements. Where
members of a nomadic culture had roamed the prairie, an industrial
civilization was rapidly growing.

Lanko tapped on the map. "Two cultures," he observed. "Two cultures,
separated by mountains and desert. Absolutely no evidence of contact,
but considerable similarity between them. This pattern begins to look
familiar."

He picked a tape from the shelves, ran it through a viewer, then
reversed it, and picked out various portions for recheck. Finally, he
made a superposition of some of their observation tape, examined it, and
turned. Banasel held up a hand.

"Don't tell us," he growled. "I studied about drones, too."

"Drones?" Musa looked at him, then glanced back at the viewer.

"Yes. Characters from one of the advanced cultures, who feel frustrated,
and fail to fit in. They often turn into pleasure seekers, and
frequently end up by monkeying with primitive cultures, to prove their
ability to themselves, at least."

"Things like this happen often?"

"Oh, not too often, I suppose, but often enough so that people like us
are stationed on every known primitive planet, to prevent activity of
the type. You see, the drones usually start out simply, by setting up
minor interference in business or government on some primitive planet.
Usually, they're caught pretty quickly. But sometimes they evade
capture. And they can end up by exerting serious influence in cultural
patterns. Some planets have been set back, and even destroyed as a
result of drone activity. Although their motives are different,
drones're just as bad and just as dangerous as any other criminal."

Lanko grinned a little. "Only difference is, they're usually easier to
combat than organized criminal groups with a real purpose. Generally,
they're irresponsible youngsters who don't have the weapons,
organization, or ability that the real criminals come up with." He
shrugged.

"Of course," he added, "we've called for help just in case. But we'll
probably be able to take care of this situation by ourselves. In fact,
unless there are unusual features, we'd better, if we don't want to be
regarded as somewhat ineffectual." H