2.

The so called "rocket ship" had crashed into the bookshop at 12:12 in the afternoon.  Everyone else in the building had gone to lunch.  Brick was busy shelving books in the new author section.  His thoughts were fixed on the awful cover designs contemporary publishers chose to catch the eye of unwary readers.  Brick preferred, as do most bumptious critics of work they do not do themselves, art from eras now lost to obscurity.  

The rocket made no warning noise.  It was not picked up by any of Earth's numerous monitoring stations.  It seemed to instantaneously materialize between the shelves of self-help romance and role-playing manuals.  It had every outward appearance of a space vehicle seen in numerous "classic" movies and illustrations of the golden age of space flight; long cylindrical shape, fins, even glass windows along the side.  The rocket was in perfect condition seemingly none the worse for crashing into a two story concrete and steel building.  

The building had come down rapidly and by some miracle of astronomical mathematics, Brick had not been crushed by the collapse.  He stood, stunned at his own survival, brushed himself off and approached the gleaming silvery tube before him.  When he was close enough to touch it a crack of light worked its way into a semi-circle along the shiny hull.  The semi-circle then indented itself and slid to one side allowing shafts of multicolored light to dance outward.  Billowing smoke ushered out of the rockets new opening, coming to settle around Brick's feet.  Brick shielded his eyes from the light and smoke, not due to any brilliance of illumination or irritation of the alien fog, but simply out of programmed reaction from watching too many "sci-fi" movies.  

He stood gaping, mouth and eyes wide.  All his mental processes fixed on the complete unreality of what he was experiencing.  That was how he met the first representatives from Dimension XZ7.  This also was the first meeting any creature from Dimension XZ7 had made of the inhabitants of Earth.  Needless to say they were slightly confused.  The creature that stood before them was nothing like what they had anticipated.  He certainly didn't match any of their scientist's postulations on life in this dimension.  The crew were about to deliberate on the awkwardness of this apparent cultural greeting (they had brought tokens of friendship for a completely different species than the one they found themselves looking at) when their on board computer spat out:

Subject confirmed.

Sentient carbon based organism.

Telemetric and harmonic vibrational match.  Error .07%

The crew of the dimensional conveyance gave a collective shrug.  This species had long ago given over their deductive reasoning faculties to computers.  As such they had come to accept what their computers told them and reacted accordingly.  This particular crew of this particular ship had been ordered to breach the dimensional vibrations and retrieve the one life form that could save their people from total annihilation.

Unfortunately their computer had made numerous miscalculations on the journey.  It reported an error of only .07% due to a circuit jump by a rogue electron.  In reality the error was much closer to 99.98%