Golden arrow
From Tardis Wiki, the free Doctor Who reference
A golden arrow was an arrow made out of pure gold.
While in 1190, the Twelfth Doctor entered a competition against Robin Hood where the prize was a golden arrow. Cheating by using an arrow with a homing beacon attached, the Doctor won the golden arrow, but it was subsequently stolen by Friar Tuck. As the Sky vessel launched, the Doctor realised that it lacked the necessary gold content to safely make it to orbit and theorised that the golden arrow might give the ship enough gold to make orbit. Working together, the Doctor, Robin Hood and Clara Oswald fired the golden arrow into the engine of the ship. The Sky vessel achieved escape velocity as a result and made it into orbit where the ship harmlessly detonated. (TV: Robot of Sherwood)
