"Elementary" fans will be in for a surprise shock as Sherlock talks relationships. But will his feelings for Fiona help or hinder him?

CBS' version of Sherlock Holmes has certainly come a long way from the protagonist's drug-related struggles in the first season. Now Holmes (Jonny Lee Miller) and Joan Watson's (Lucy Liu) professional relationship is stronger than ever, even though their personal lives are fraught with dilemma.

Despite that, the cantankerous Holmes has been doing his best to become a better person and has even begun to move on from his disastrous romance with Irene Adler. However, the detective might be in danger of going back to his old ways.

A synopsis for episode 18, "Ready or Not," teases that Holmes and Watson have a challenging task ahead of them as they try to determine whether a missing survivalist doctor has "purposely gone off the grid or if he's a victim of foul play." Holmes' personal life will also be in the spotlight when he starts behaving oddly when his romance with Fiona (Betty Gilpin) hits a stumbling block.

"Elementary" fans will certainly agree that feelings and relationships are probably two areas where Holmes struggles, despite his high IQ. So it might come as a pleasant surprise for some to see him really making an effort. The trailer starts with Sherlock talking about the "one great romance" of his life. He describes Adler as being more than a girlfriend, while one scene shows Sherlock and Irene walking out of an establishment. He seems to be helping her stay upright and walk. Viewers then see Fiona looking for Sherlock at home. The detective then admits that relationships are hard for him; Fiona gets up and walks to him. The truncated trailer asks if "a new love can heal old wounds," and the way Fiona approached Sherlock, there's a chance that she might understand him better now.

The series has done a good job at developing the various characters through the cases they handle, the people they encounter, and their own personal struggles. Unfortunately, it might all be drawing to a close as season 4's finale is set to be aired on May 8 and there's no word yet on whether the show will be picked up for another season.

Episode 18 of "Elementary" season 4 will be aired on March 27.