Magia Record Story The Chiming Bell that Transcends Time
The following is a summary posted on 4chan's /pmmm/ general by Summary Anon.
Part 1
There is a spoiler that indicates this story happens shortly after the Nanami family get back together after the Magius brainwashing fiasco.
Iroha and Yachiyo are visiting Mitama's shop, where Mitama talks about an orthodox spell dating back to medieval Europe which helps the user to sleep well and have a good dream. Yachiyo is interested in it since she has been having trouble sleeping lately, and Mitama gives them the spell and gives them a pair of incense candle to go along with it.
The pair tried the spell that night and fall asleep smoothly, but Iroha wakes up and find herselfs in the middle of a forest and hearing the noises of an ongoing battle. She is assaulted by soldier-like familiars and was saved just in time by Yachiyo. Iroha also transforms and defeats the soldiers with Yachiyo, and the Puella Magi leading them joins in the fray.
She is ridiculously powerful and is going in for the kill on Iroha when Tart barges in and tanks the attack with ease. She urges them to retreat as she tanks the enemy, and the pair heed her advice since Iroha is not in a shape to fight. They noted that the witch that is also rampaging is one of those from Kamihama and wonder if this is because this is part of the dream. Tart tanks the attacks from the enemy Puella Magi, and with Riz's help forces the enemy into retreat. Yachiyo notes that Tart is also called La Pucelle and wonder if she is Jeanne d'Arc. Melissa is there to help the pair, and they note a huge magical energy burst and receive a confirmation from Melissa that it is Jeanne's. The two slowly wake up from the dream.
The next day, the pair shared their dream with the rest of the family and it is revealed that only they shared the dream. Yachiyo comes to the conclusion that it is either the candle or the spell that has caused the dream. Calling Mitama, Mitama apologizes for the experience and is also puzzled since everyone that has tried the spell has had good sleep and dreams. Yachiyo comes to the conclusion that the candles are the cause.
Out of curiosity, Iroha and Yachiyo try the spell and candles again and are indeed brought back to the same dream. They appear in Tart's camp who is glad the pair are safe since they seem to fade into nothing from Tart and friends' point of view. Yachiyo confirms with Tart that she is indeed Jeanne d'Arc and is surprised Yachiyo knows her full name since she goes by Tart. This alarms Riz, but before anything can be done on the issue, a small child barges in and pleads for Tart to help her sister who is caught by monsters. Tart naturally agrees, and Iroha also joins in despite it being a dream since she can't bare to see others suffer.
Together, they enter the witch barrier, and realize the culprit is a witch from Kamihama. Under Iroha's guidance, the group easily beat the witch and rescue the child's sister. Iroha feels good doing good despite it being a dream to which Yachiyo also agrees. The conversation goes on to the reason Tart became a Puella Magi: to ensure the tragedy of her sister's death isn't repeated on other people, thus she choose to become a Puella Magi to liberate France.
Tart then reveals that Orleans has fallen and she has suffered numerous defeats which alarms Yachiyo since Jeanne was supposed to lift the siege and turn the tide. Melissa adds that after the defeat at Orleans against the enemy Puella Magi who suddenly brought in unlimited reinforcements in the form of soldier familiars, night has reign and they have not seen the sun since.
Yachiyo notes that this is like a dream, to which Riz responds a little angrily that to them it might be a dream, but to Tart and the others this is reality, at which Yachiyo apologizes. The spell seems to go off and the pair woke up again.