In truth, Davis called Clara way before Evelynn came back. He was recuperating and couldn't leave, according to his wives, so to not waste time, he called Clara here as she was waiting for him in her room. He did say that he wanted to talk to her privately, after all.
But as she was here, he had a certain idea and thought of using how a brother-sister combo of finding the truth would work.
With his Enigmatic Heart Intent and Clara's Transcendent Truth Eyes, almost nothing could escape their senses. Lies could be seen through, and hidden emotions could be clearly felt. It was the perfect combo to counter deception.
Davis merely wanted to test on this unsuspecting woman their ability to work together, but it turned out that she was a Divergent.
