Short story from book #2

Dear friend, have you a few free days? I go to Boscombe Valley to solve the case some man,s son. I would be, that you go with me.

I agree this offer and he told me details of story about the man.

The story involved two families: family of John Turner and family mr Charles McCarthy. The men met at work in australian mine. Both became very rich men and brought money to England. They settled in Boscombe Valley. One of the men, mr Turner was rich, but McCarthy became his tenant. Turner has 18 years old daughter and McCarthy has son in the same age.

On Monday McCarthy left house and going to Boscombe pool, but never came back. Two alien men told, that they saw him alone. One of the man added, that he saw his son in the same place.