when do they find out who red coat is
Red Coat (Pretty Little Liars) In the fourth season's mid-season finale "Now You See Me, Now You Don't", the Liars head to Ravenswood to look for Red Coat. While there, Red Coat kidnaps Emily and locks her in a coffin on a Sawmill. The Liars witness Red Coat heading to that Sawmill and chase her inside, where she actually stops the saw and another Red Coat, donning a mask of Alison's face, appears on the stairwell, revealing that two people have been sporting the disguise all along. Spencer follows the "good" one, while Aria fights and unmasks the other figure as CeCe Drake. The Liars manage to catch the "good" Red Coat near the ending of "Grave New World", who reveals herself as an alive Alison. During "EscApe from New York", Ali claims that she asked CeCe to wear the disguise to distract "Big A". It is later revealed this was all a ruse, given that CeCe actually was the Red Coat who stole the game from Mona and wore the disguise during her schemes until she was caught in it. In "Game Over, Charles", the Liars learn there was a third Red Coat who posed as a decoy to CeCe and used the infamous disguise to distract the Liars whenever she couldn't. The third Red Coat is revealed to be Sara Harvey.
Red letter day A red letter day (sometimes hyphenated as red-letter day or called scarlet day in academia) is any day of special significance or opportunity. Its roots are in classical antiquity; for instance, important days are indicated in red in a calendar dating from the Roman Republic (509–27 BC).[1] In medieval manuscripts, initial capitals and highlighted words (known as rubrics) were written in red ink. The practice was continued after the invention of the printing press, including in Catholic liturgical books. Many calendars still indicate special dates and holidays in red instead of black. The practice did not originate,[citation needed] as is often assumed, from Medieval church calendars or a requirement that important holy days be marked in red from First Council of Nicaea in 325 AD, as has widely been claimed.