Episode 10 of "No Tail to Tell" begins with Eun-ho and Si-yeol arriving at the hospital. Pagun pulls Eun-ho aside and scolds her for meddling with human destiny. Si-yeol was meant to experience a life that would rise and fall swiftly (i.e., die), while Woo-seok was destined for a long but challenging existence. Pagun returns her blade to her, instructing her to kill her true love, which will rectify their fates and turn her back into a fox. Failure to do so will result in her death as a human, according to Pagun.
In a daze, she returns to Si-yeol, who is relieved that Woo-seok is alive. On their way home, she wonders what makes Woo-seok so special. Si-yeol replies that they know each other's deepest flaws but are willing to sacrifice for each other. She wonders if the same applies to them—whether they would resent each other if Woo-seok dies or Eun-ho remains human forever. However, she rejects the options offered by the Heavens. She will regain her powers and remain by Si-yeol's side forever, saving him every time he needs it.
Later, we learn that Woo-seok has late-stage heart cancer and has less than six months to live. Shocked, Woo-seok realizes that he is not meant to die, but Si-yeol is. Elsewhere, the fourth division teammates find the football field locked. Coach Yong-gil is busy trying to find a sponsor and has canceled training. Geum-ho 2.0 shows up and unlocks the field. Beom is attracted to her and convinces the team to have lunch with her instead.
Meanwhile, Woo-seok calls Si-yeol and Eun-ho to the hospital. He apologizes for getting greedy and tries to manipulate Si-yeol into switching their fates immediately. Eun-ho is furious and sends Si-yeol out on the excuse of buying a gift basket for Woo-seok. She criticizes Woo-seok for being rude but promises to keep his motives a secret to protect Si-yeol's view of their friendship. However, she has an idea that requires Woo-seok to make a deal with her.
Beom takes Geum-ho 2.0 and the team to a pool hall where he plans to show off and then treat her to an elaborate meal. She is delighted but he is terrible at pool. He sulks as the loser needs to treat the rest of the team as well. She jumps in and, using magic, wins the game for Beom.
Back at the hospital, Eun-ho drags Si-yeol away to return the gift basket. They reach the store which happens to be the one that fired Eun-ho. Si-yeol decides to resolve her debt but is surprised when the manager turns out to be Yeon-su, his past life agent.
Eun-ho's delight at payback quickly transforms into a seething jealousy as Si-yeol befriends Yeon-su and even invites her along with Hye-rim, another part-time worker, for dinner. They learn that after Yeon-su had children, the gap in her resume made it difficult for her to return to the sports industry. Si-yeol decides to enlist her help in managing his team, with the primary goal of finding a sponsor.
At the pool hall, another teammate, Jeong-bae, falls for Geum-ho 2.0. However, she only has eyes for Beom, and as the two flirt, the other teammates become uncomfortable, pitying Jeong-bae. Similarly, it becomes awkward for Yeon-su as Eun-ho glares at her and pays the bills with Woo-seok's black card. Once Yeon-su and Hye-rim leave, a jealous Eun-ho sulks that Si-yeol didn't pay attention to her. Apologetic and endeared, he explains that he felt bad that, along with him, Yeon-su's career had tanked. Eun-ho reasons that meeting the right person can change someone's fate.
Right then, Hye-rim calls as she has accidentally switched phones with Eun-ho. Her phone screen shows that she is the daughter of Go Bong-chang, the driver killed by Lee Yoon. With Geum-ho 2.0's help, Eun-ho and Si-yeol stalk her and learn that she has taken up as many part-time jobs as she can. Her mother had a breakdown after her father died, and medical and college bills have piled up. Eun-ho decides to make things right with her by creating an Eunho Scholarship Foundation at the college of Hye-rim's choice and plans to take care of her housing and medical bills.
On top of that, Eun-ho starts splurging on the nursing home and lavishing Si-yeol's grandma with gifts. She also charters a fancy bus for the team's away game, pays back Gyeong-hun, a teammate, for abandoning his car during the hike, and tags along.
Midway, Coach Yong-gil gets a call for a sponsor meeting and runs off. It cuts to the sponsor meeting which also includes Yeon-su and the sponsor...Lee Yoon. She wonders about his motives and he claims he is interested in the football team in more ways than one.
Geum-ho 2.0 decides to stop by her cave home before joining the team at their away game when she finds Do-cheol waiting for her. He has bought a vajra bell, a cursed tool with Yoon's money. To bewitch her, he rings it and channels divine energy.
In the bus, a sleeping Eun-ho dreams of Pagun warning her that if she messes with fate, events she cannot predict will come crashing down. It cuts to her dream of Si-yeol stabbing her.
