The Destruction of Everlue Mansion

The Destruction of Everlue Mansion is an event during the Daybreak arc where Natsu, Lucy, and Happy skirmish with Duke Everlue and the Vanish Brothers about the book, DAYBREAK.

Prologue
After arriving at the Everlue Mansion, due to Lucy's unsuccessful attempt to seduce the owner, Team Natsu decides to infiltrate the building. They eventually come across the library where they find DAYBREAK in the library. Duke Everlue finds them, along with the then-arriving Vanish Brothers. Lucy starts reading DAYBREAK after discovering whom the author is and decides to read it more in secret after declaring that there may be a secret inside. Hearing this, Everlue greedily chases after her with Happy flying towards them. This leaves Natsu alone with the Vanish Brothers.

Body vs Mind
Natsu and the Vanish Brothers converse with each other before going on the offensive, striking at Natsu and damaging the mansion. The elder Vanish Brother begins lecturing him about the weakness of Mages, which is the "body" since Magic only relies on strength in the "mind". He repeats that Mages lack genuine power but Natsu points out that none of his and his brother's attacks are reaching him.

The Vanish Brothers then perform a combination attack on Natsu, claiming no one has lived after being hit, but to their shock Natsu emerges virtually unscathed and somewhat disappointed. He performs Fire Dragon's Roar on the two but the elder brother reflects the attack back at him with Flame Cooking. However, being a Fire Dragon Slayer Natsu is unaffected again and attacks the Vanish Brothers, burning them both to a crisp.

Clash With the Mansion Owner
Meanwhile, Lucy finishes reading and deciphering DAYBREAK, deciding in the end that she can't destroy it. Suddenly, Everlue appears through the wall and restrains her arms. Everlue threatens her into revealing DAYBREAK's secret when suddenly Happy attacks him, freeing Lucy. Lucy converses with Everlue briefly about DAYBREAK and while they do, both begin fighting. As they do, Everlue revels in how he made Kemu Zaleon write the book using a cruel threat. Lucy becomes angry and as she yells to Everlue, she states that Zaleon was a Mage himself and that he cast a spell on DAYBREAK. She adds that she won't return the book to Everlue as he is unworthy of possessing it.

She summons her Celestial Spirit Cancer and Everlue summons Virgo, also one of his maids. However, Natsu appears as well due to being with Virgo when she was summoned. She and Natsu fight against Everlue and Virgo, quickly defeating them. A happy Lucy clutches onto DAYBREAK.

Aftermath
Natsu, Lucy and Happy then return to Shirotsume Town to return the book to Kaby Melon. Everlue is arrested shortly thereafter and Virgo's key is eventually transferred over to Lucy.