Meanwhile, a sculptor named Farhad falls in love with Shirin and becomes Khosrow's love-rival. Khosrow cannot abide Farhad, so he sends him as an exile to Behistun mountain with the impossible task of carving stairs out of the cliff rocks. Farhad begins his task hoping that Khosrow will allow him to marry Shirin. Yet, Khosrow sends a messenger to Farhad and gives him false news of Shirin's death. Hearing this false news, Farhad throws himself from the mountaintop and dies. Khosrow writes a letter to Shirin, expressing his regret for Farhad's death. Soon after this incident, Mariam also dies. According to Ferdowsi's version, it was Shirin who secretly poisoned Mariam. Shirin replies to Khosrow's letter with another satirical letter of condolences.