The Book of Love

The Book of Love is a quest that begins in the Temple of Mara in the city of Riften. It is given to the Dragonborn by Dinya Balu, one of the priestesses, when asking for the Blessing of Mara. To earn the Goddess of Love's favor, Dinya sends the Dragonborn to the village of Ivarstead to help a local girl with a love problem.

Riften
This quest is easily located by entering the town of Riften and following the path on the left towards Mistveil Keep. The Temple of Mara is clearly marked by a pair of guards standing before an opening in the stone wall with twin banners hanging behind them. Enter the Temple and speak with Dinya Balu, the Head Priestess of the Temple, and request Mara's Blessing. She will say that one must prove themself worthy of the blessing by advancing the cause of love throughout Skyrim, and relays a vision sent to her by the Goddess to visit a small village called Ivarstead to the west of Riften. Head west to Ivarstead.

Ivarstead
Arriving at the hamlet of Ivarstead, the quest prompt is to speak with a girl named Fastred, who is in something of a conundrum with her parents. Fastred fancies herself in love with a local man named Bassianus, but her parents disapprove of their choice to leave Ivarstead for Riften. After speaking with Fastred, speak with her mother and father as well. Speaking with the mother will reveal that she does not disapprove of Bassianus, and would allow the pair to elope while she took care of informing her husband. Speaking with Fastred's father will show he thinks his daughter is a rather fickle young woman whose affections change frequently. He will state that, up until very recently, Fastred was infatuated with another local man by the name of Klimmek, and that he is concerned that Fastred will leave the rapidly shrinking village for good if she chooses to leave with Bassianus.

There are two choices: Head to the local inn to inform Bassianus that Fastred's mother is willing to run interference so that he and his love interest can elope to Riften, or investigate Klimmek's past relationship with Fastred. Confronting Klimmek will result in the fisherman realizing that he must be assertive with his feelings for Fastred, and let her know that he wants to be with her. Speaking with Bassianus will result in Fastred and Bassianus eloping to Riften, never to return to Ivarstead. Choosing either will result in the quest advancing.

Next, return to Riften to learn that the Goddess requires a journey far to the west, to the city of Markarth to stoke the flames of love in the heart of Calcelmo, the eccentric Dwemer researcher and court magician in Understone Keep.

Markarth
Calcelmo is having some lady trouble. He's attracted to a woman named Faleen, who works in the keep, but has no idea how to speak with her. Fearing the possibility of offending her in some way by bringing up the wrong subject, Calcelmo asks the player to get advice from a friend of Faleen's named Yngvar, who is reputed to be quite successful with the local ladies. This ladies-man can be found in the Treasury House at night or in the Silver-Blood Inn by day. He is also often found resting against a rock by the stream, just opposite the Abandoned House. If Stormcloaks have taken the city, he will be the new Jarl's housecarl. He will reveal that Faleen puts on a tough front, but has a weakness for poetry. It just so happens that Yngmar has a poem that he can tweak to be about Faleen... for a sum of 200 gold. Pay the piper and take the poem back to Understone Keep and speak with the lucky lady. After prompting Faleen to read 'Calcelmo's' poem, she will ask that a letter be delivered to the bumbling researcher. Head back to Calcelmo, give him the letter, and proceed to follow him and witness his stumbling confession. If Faleen is in Solitude, it will take several hours for Calcelmo to walk all the way from Markarth to Solitude so it is recommended to proceed with other quests until a notification shows up in the quest journal that Calcelmo has spoken with Faleen, or just wait for four hours and he will be there. With the job in Markarth complete, return to the Temple of Mara for the next objective.
 * If Stormcloaks have taken Markarth, Faleen will be found in the lower floor of the Blue Palace in Solitude, rather than Understone Keep. Yngvar will be in the Understone keep as the Jarl's housecarl.

For the final task, Mara requests that two lovers be reunited who have lost one another beyond the pale of death.

Gjukar's Monument
Put on the amulet given and travel south-southeast of Rorikstead to find the spirit of Ruki, looking for the body of her husband among the ruins. Speak with her and she will ask for help looking for her husband's body. With no corpses present in the area, head northeast towards an open plain. The spirit of Ruki's husband is just south of Greenspring Hollow on the south side of that river. Speak with him and he will ask to be led back to Ruki. At this point, one can choose either to fast travel back to Gjukar's Monument, or take the scenic route. After reaching Ruki, the two dead lovers will speak briefly, and ascend towards the heavens as they pledge eternal love for one another. They are confused because they do not know that they are dead.

Return to Riften and speak with Dinya Balu to receive the Agent of Mara blessing (Permanent +15% Resist Magic) and complete the quest.

Trivia

 * The name of the quest may be a reference to the song "The Book of Love" by the Magnetic Fields, also covered by Peter Gabriel.

Bugs

 * Fastred and Bassianus may stay in Ivarstead even though helped to elope to Riften. Both of her parents will comment on her being in Riften even with Fastred standing in full view of them. Its possible this is from starting the dialogue with Klimmek then exiting it and finishing the quest by talking to Bassianus instead to help the couple elope.
 * If the player doesn't complete this quest immediately and goes on to acquire another Amulet of Mara, (in addition to the one given by the priestess at the beginning of the questline), there may be a bug in which the player cannot complete the quest stage "Put on the Amulet of Mara." This is especially prone to happen if the player has a stolen Amulet of Mara in their inventory. To fix this, stash all stolen items which one wishes to keep in a safe container, and then commit a small crime. When approached by a guard simply pay the bounty and allow them to remove the stolen Amulet of Mara. This will then allow completion of the quest.
 * If the player speaks to Bassianus but does not then watch him speak to Fastred, the quest may not register as completed. Entering the Fellstar Farm house and watching their interaction will complete the quest.
 * If Ruki's husband Fenrig is talked to, a glitch may occasionally occur where the dialogue box appears, but Fenrig does not respond to the choice in the box. To fix this, at least on Xbox, just save after trying to talk to him, then reload the save.
 * Occasionally, after bringing Fenrig to Ruki, one or both of them will gain their normal character model under the ghost texture.
 * There is a glitch where the player is not able to ask for Mara's Blessing and therefore can't start the quest, (Dinya Balu must be approached while inside the temple for the dialogue option to appear).
 * If the Stormcloaks have taken Markarth then Calcelmo will run to the Blue Palace which can lead to, (if the game views him as killable), him possibly dying on the way, failing the quest.
 * Once completing the quest the player becomes over encumbered, (at least 12 weight increased making the player 1 weight over), presumably by the Amulet of Mara, even though the amulet only weighs 1. Once removed from the inventory the player is still over encumbered although they were not when they entered the room. On reload from an auto save just before the player fast traveled, the player is once again over encumbered by 1
 * Note: No carry capacity effects active before receiving Amulet of Mara. On reloading from a Quick Save Before the player finds Ruki, carry weight is Normal. (Needs confirmation)
 * Note: tested on PC with 2 amulets of Mara in possession, both labeled as quest items for the duration of the quest, and, as such, weightless, (even though their weight is 1 in inventory). After completing the Ruki & Fenrig stage, the amulets reverted to "normal", (non-quest), status, and so regained their weight, (+2 extra encumbrance).
 * More like an amusing oversight than a bug, if the player doesn't tell Yngvar that Faleen's secret admirer is Calcelmo, he still signs the poem "from Calcelmo to Faleen".

Appearances

 * The Elder Scrolls V: Skyrim