Once you're back to room 208, enter the bedroom on the left side and examine the clock. Use the clock key to open the face of the clock.
"Read the memo on the table and you'll get some clues.
Examine the scratches on the wall for more clues to this puzzle. So we already know that Scott is at 15. meaning he can't be the hour hand. Time to check back on the clock.
If you try to move the hands, you'll notice that you can only move the hour and minute hands. Also that the second hand is permanently stuck at 3. So we already know that this is Scott and we're left with moving hours and minutes. If you remember the scratches on the wall they're named Henry, Mildred and Scott, in other words Hours, Minutes and Seconds. All that's left to do is copy the position of Henry and Mildred.
So place the clock at 9:10 and you'll hear a sound of something unlocking.