“But if he was in Nashville—­”

“If he was, then he’s safe.  But he himself cannot prove that he was.  And I tell you frankly that the police will investigate his movements very carefully.  It strikes me as exceedingly peculiar that he checked out from the Hermitage Hotel at four o’clock in the afternoon when he intended taking a two a.m. train.  Remember, I am accusing your husband of nothing.  Our conversation could have been pleasant—­he refused to allow it to be so.  He classified me as a professional detective and put me on that basis in his home.  I have merely accepted his invitation to act as one.  If I appear discourteous, kindly recall that it was none of my doing.”

“I’m sorry, Carroll,” said Lawrence pleadingly.  “I didn’t know—­”

“Of course you didn’t know how much I knew—­or might guess.  You saw fit to insult me—­”

“I’ve apologized.”

“Your apologies come a trifle late, Lawrence.  Entirely too late.  Our relations from now on are those of detective and suspect—­”

Again the flare of hate in Lawrence’s manner:  “I don’t have to prove an alibi, Carroll.  You have to prove my connection with the thing.  And you can’t do it!”

“Why not?”

“Because I was in Nashville at that time.  And while perhaps I can’t prove I was there—­you certainly cannot prove I was not.”

“That remains to be seen.  Meanwhile, I’d advise you to establish that fact if you can possibly do so.  And by the way:  are you in the habit of indulging in these solitary debauches in neighboring cities?”

Lawrence flushed.  “Sometimes.  I used to be a heavy drinker, and—­”

“Is that a fact, Mrs. Lawrence?”

“Yes,” she answered eagerly:  almost too eagerly Carroll thought—­“he has had escapades like this—­several times.”

“And you are sure that his story is true?”

“Yes.  Of course I’m sure.  Why should he kill Mr. Warren?  There isn’t any reason in the world—­”

“For your sake and his, I hope not.  But meanwhile—­”

“Surely, Mr. Carroll—­you don’t intend publishing what he has told you—­about his drinking—­alone—­in Nashville?”

Carroll smiled.  “No indeed.  In the first place, I am not at all sure that he has told me the truth.  In the second place, if I were sure of it—­his alibi would be established and I have no desire whatever to injure a man because of a personal weakness.”

Lawrence stared at Carroll peculiarly.  “You mean that if I can prove the truth of my story, nothing will be made public about my—­the affair—­in Nashville?”

“Absolutely.  Because you have treated me discourteously, Lawrence—­I don’t consider myself justified in injuring your reputation.  I am after the person or persons responsible for the death of Roland Warren.  Your intimate weaknesses have no interest to either me or the public.”

Lawrence was silent for awhile, and then—­“You’re damned white, Carroll.  The apologies I extended a moment ago—­I repeat.  And this time I’m sincere.”