1. When he came in, Lewis immediately noticed that the butler  had vanishedhas vanished.

2. He suspected that he  had donehas done something unforgivable and didn't want to raise suspicions.

3. “ Had you seenHave you seen the butler recently, Mr Johnson?” he asked.

4. “Well,” Mr Johnson answered, “I think he  had been invitedhas been invited by his aunt for the week-end. Why are you asking?”