You are dividing the sentence incorrectly. "Hustle" is simply a verb, with its ordinary meaning. "Through" is a preposition that begins the prepositional phrase "through the smallish, spare lobby." You could have many different verbs, and keep the preposition: Guests runthrough the lobby.
Guests walkthrough the lobby.
Guests stagger through the lobby.
Gursts drivethrough the lobby.
Guests ride bicycles through the lobby
And so on...