Meet the janitor at Moscow Elementary School #37. Matveich spends a lot of time down in the basement, and doesn't always hear when people knock on the door, because he's "half deaf" (14.1). Sasha thinks Matveich is lazy, a bit ignorant, and more than a little suspicious.
See, Sasha's convinced that the old guy's hiding something in the storage room (14.2)—something fishy. But the budding Young Soviet Pioneer changes his mind when Matveich demands that Sasha get the principal's signature on Nina Petrovna's order to release the Young Soviet Pioneers banner to Sasha. To Sasha, this exercise in proper bureaucratic procedure shows that Matveich is "vigilant" (14.8), because there are spies and wreckers lurking around every corner dontcha know.