Episode 620

"A Critical Situation! Punk Hazard Explodes" is the 620th episode of the One Piece anime.

Short Summary
Monet was moments away from activating the self destruct button when she felt her heart being stabbed and collapes before dying. At the same time Caesar Clown stabbed the heart believing it to be Smoker's heart. The Straw Hats are still racing towards the exit of the collapsing lab when they felt the explosion of the SAD room and then saw Shinokuni on their trail. Smoker, seeing that they nearly reached safety, questioned Trafalgar Law of why did he possessed his heart the whole time. Trafalgar Law reveals the clever deception he played on the mad scientist where he returned the heart of Monet to Caesar without Caesar being the wiser.

At the tanker, Baby 5's missile attack failed to take down Franky Shogun and their duel began anew whereas Buffalo contacted Doflamingo of the situation. After confirming that the island wasn't destroyed as intended, Doflamingo decided to tend to the matter himself and is seen somehow flying over the sea towards Punk Hazard.

Anime Notes

 * When Caesar stabs Monet's heart, the hole on Monet's chest wasn't shown in the anime.
 * In the anime, Caesar stabs Monet's heart at the same time the SAD room explodes. In the manga, the SAD room explodes before Caesar stabs her heart.
 * The anime shows that Law gives Smoker back his heart after finding the rail car while the manga did not show exactly when Law returned the heart.
 * The anime adds the following:
 * After Zoro cuts a large piece of rubble blocking the passage, everyone in the rail car cheers for him.
 * The deadly gas chases after the rail car.