I hope I'm not asking you too much but I'm having trouble of understanding part of a paragraph. Would you rephrase it or answer my questions down blow.

The paragraph begins with this:
The crew is steering straight into a perfect summer at the Jolly Roger Hotel. During the day our trustworthy manager holds the line. At night they entrust this gorgeous beast of a hotel to me.

holds the line:
Does this have any other meaning than "waiting for someone to answer the phone"?

a hotel:
The main character is a hotel clerk working at the Jolly Roger. So I think it has to be "the hotel" not "a hotel."

I know all the meanings of the words in this paragraph, and yet, I cannot make sense out of it. I must be misunderstanding something. Please help me out.

Thank you in advance,
...manager holds the line = he makes sure that business runs as usual/he maintains a normal state of affairs

this gorgeoous beast of a hotel. (this structure is very idiomatic)

For instance you could say

She's a beauty of a woman.

He's one heck of a man.

This is a monster of a car.
thank you. now it made sense to me.Emotion: smile