The idiom ‘bolt from the blue’ means:

The idiom 'smell a rat' means

He cannot get that contract. It is a wild goose chase. (Meaning close to the idiom underlined)

The idiom ‘ivory tower’ approximately means :

Give the meaning of the following phrase get at.

Replace the word underlined by right phrase given:

Since the weather is bad, we will cancel the meeting arranged for this evening