Perhaps it had not been necessary to convince him of the conspiracy.
When he had finished his figures he reviewed them, tracing each total with his pencil's point; then quietly handed the pad to Mortimer who went over it, and nodded that it was correct.
Lydia rose.

Quarrier said, without looking at her: "I have a blank cheque with me.

May I use one of these pens ?" So he had brought a cheque! Had he supposed that a cheque might be necessary when Lydia called him up?
Was he prepared to meet any demand of hers, too, even before Mortimer appeared on the scene?
"As long as you have a cheque with you, Howard," said Lydia quietly, "suppose you simply add to Mr.Mortimer's amount what you had intended to offer me ?" He stared at her without answering.
"That little remembrance for old time's sake.

Don't you recollect ?" "No," said Quarrier.
"Why, Howard! Didn't you promise me all sorts of things when I wanted to go to your friend Mr.Siward, and explain that it was not his fault I got into the Patroons Club?
Don't you remember I felt dreadfully that he was expelled--that I was simply wild to write to the governors and tell them how I took Merkle's clothes and drove to the club and waited until I saw a lot of men go in, and then crowded in with the push ?" Mortimer was staring at Quarrier out of his protruding eyes.

The girl leaned forward, deliberate, self-possessed, the red lips edged with growing scorn.
"That was a dirty trick!" said Mortimer heavily.