What is going on with this man?

Hint 1 of 9:

To discover his problem, finish writing the letter on the desk.

Hint 2 of 9:

Explore the room carefully.

Hint 3 of 9:

Open the desk drawer and wave your hand over the necklace.

Hint 4 of 9:

Look at the fireplace, all of the portraits and furniture.

Hint 5 of 9:

Stare out the windows.

Hint 6 of 9:

Look at the book under the young woman's portrait. (Is this a young
Berenice?)