'Dreek', a mixed breed with a legend that was born from the true love between a human and a dragon. Although they had the appearance of humans, their extraordinary physical abilities and resilience resembled those of dragons. Even the heat that comes periodically. Among such 'Dreeks', Cyric became a uniquely strong knight due to the strong dragon's blood. While heading to the ruins after receiving the king's order to rescue researchers stranded in the ruins, He encounters Jahid, a petty thief who tries to steal his sword made of dragon bones. Just as he is about to give the thief a fitting punishment, Cyric unexpectedly comes into heat and is unable to find a suppressant, putting him in trouble. Jahid, who notices Cyric's condition, quickly proposes a deal, saying that he is also Dreek...