Complex sentence: Richard has no time for either of them, so instead they both pace back and forth outside the compartment, Gander making silly faces until at last Richard loses patience and shuts the blinds over their windows.
Split into simpler sentences: Richard has no time for either of them, so they both annoy him by pacing back and forth outside his compartment. Gander makes silly faces until Richard loses patience and shuts the blinds over their windows.