Two men discovered the trap door in a back room. (How many)

They discovered 23 religious murals. (What kind)

Arthur was an artist. (What)

Arthur heard the coin hit the floor. (What)

Arthur pulled the knife out of his pants pocket. (What)

Arthur started searching. (What)

Arthur began digging with his knife. (What)

The floor board suddenly loosened. (What)

Eric helped Arthur remove four floor boards. (Who)

The hole was about 15 feet long, 10 feet wide, and 2 feet deep. (How)