Arrow is one of the hottest TV shows on CW, but unlike The Flash, the show is stumped in realism. However, that will soon change with the introduction of the Lazarus Pit.
By now, every comic book fan should have an idea what the Lazarus Pit is, and what it is capable of doing. For those who are unaware, the Lazarus Pit is the very thing that allows Ra's al Ghul to be immortal. Every time he ages, he goes into the Pit become younger again.
The Lazarus Pit isn't only for keeping folks ageless; it is also great for healing severe wounds and bringing someone back from the dead. Yes, the Pit is that powerful, and it could be the reason why Sara Lance will return to Arrow, because from all indications, she is dead and has been buried for quite some time.