Possible Clues:

• Phone to hire out small band
• Girl, ten, let loose curl
• Some of Barnet gang joining obstruction
• Lock of hair found inside covering letter
• Lock service that's replayed after call
• Thriller with intro and finale swapped in a twist of sorts?
• Lock where key may be found a hindrance
• Surround the foreign boat at the bottom of lock
• A lock of hair gave Romeo a peculiar tingle.
• Small curl of hair