continue with their mischief until one of them notices kafka coming and nudges the other so strongly he almost falls over. they're both standing at attention, looking guilty, by the time kafka arrives.
one is sweeping the floor. the other is scribbling at their desk. his pen blotches his paper. he has a fit and crumples it up and throws it down.
the sweeping one bangs his knee against a desk and starts hopping about. the pen of the other one leaks again. he crumples up his new sheet and flings it away even more angrily than before. then he examines his pen, determines that the cap at the back is loose, and starts banging it on his desk in an attempt to tighten it -- while the other assistant keeps jumping around holding his hurt kneecap.
the one assistant has just fixed his pen when the other one, still hopping around, bumps into him, causing him to knock over a bottle of ink. the two of them start shoving each other about.
jump in unison when the bell goes off. then in their hurry to leave start shoving all their papers and whatnots haphazardly into various drawers, opening and slamming them regardless of whether or not the contents are fully inside, resulting in a lot of crumpled documents and snapped pencils.