Two cases, two detectives. Seems simple enough, but Sherlock begins to question Joan’s work with Hannah Gregson on tonight’s Elementary.

The Captain’s daughter, and fellow member of the NYPD, requests Joan’s help on tonight’s Elementary season 3, episode 20, “A Stitch in Time.” Joan is not the only one looking to help out a friend in need. Sherlock finds time to invite another client into their home that causes quite the ruckus and casts Joan out of the brownstone yet again.

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Previously on ‘Elementary’

Sherlock and Joan found themselves in the center of Everyone’s civil war. The hacker collective took opposing views on how to handle their control of the infinite resources at their disposal. In the end, the good guys won and the group backed away from nearly performing a hack that would cause them all the commit treason and bring one FBI agent job security.

Sherlock is troubled when Joan’s recovery from Andrew’s death leads her to adopt his more hermit style traits. He encourages her that it is in the interest of their partnership and their friendship to encourage the other’s best attributes, not mimic their worst.

This week on ‘Elementary’

The bees are back, but not on the roof where they belong. As Sherlock attempts to solve colony collapse disorder, two more cases arrive for the detectives. One involves the murder of a skeptic and requires a thorough investigation of a congregation who was targeting him. The second is for Captain Gregson’s daughter Hannah, who consults Joan to help track down a few leads.

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Watch two clips from tonight’s episode here.

Watch Elementary season 3, episode 20, “A Stitch in Time,” tonight at 10:00 p.m. ET on CBS.