"Suits" Season 6, Episode 14 is titled "Heartburn." The episode features one of the main characters suffering a heart-attack. It seems that it is either Louis or Harvey who has a heart-attack.
In the preview clip, Jessica can be seen telling Donna that "he had a heart attack in court this morning." The clip does not reveal who suffered a heart-attack in the episode. The preview, however, shows Donna breaking-down at the patient's bed-side, saying if anything happened to you.... This is making some fans speculate that it must be Harvey. Mike looks serious and sombre but not too affected in the preview clip, which is making a majority of "Suits" fans speculate that it is Louis. The official synopsis of "Heartburn" indicates that Louis will face a huge challenge. It can be speculated that the huge challenge may have caused the heart-attack.
According to the spoilers, the danger to the life of one of the main characters is going to make all the characters come together. Gabriel Macht, who plays Harvey Specter, had said during the USA TCA Press Tour, as quoted by Buddy TV, the characters will huddle around and become a real family.
"... in one of the episodes that you'll see when it comes out March 6th, one of these characters' life is in danger, and you see that we do, sort of, huddle around and become a real family for each other. And so I think that that idea of love, it is a major theme," Macht had said.
Meanwhile, the synopsis of Episode 14 suggests that a big client will make Mike and Harvey do some unpleasant work. Harvey may also have to pacify Scottie and make her believe that theirs is a relationship of trust. In the previous episode, Harvey and Scottie's relationship hit the roadblock when he refused to reveal why he owe Louis a favour. Also, he said to Scottie that she is talking to the named partner of the firm, not to her boyfriend. In the episode, Harvey may have to take huge steps to fix their relationship. The preview clip, however, does not provide a glimpse of Scottie.
Official Synopsis of "Suits" Season 6, Episode 14, "Heartburn": "While Harvey and Mike have unpleasant work to do for one of their biggest clients, Louis faces a huge challenge in Suits."