Book of Elements

The Book of Elements arc is the fourth arc in the LEGO Ninjago series. Every installment is an Elemental titled "chapter" that focuses on one or multiple Ninja. Each season builds the plot up to the final confrontation with the Crystal King.

After facing the greatest evil the world will ever see, the Ninja have some down time. Each season in this phase "retells" the original seasons of the past through the enemy variety, almost in the right order. This phase is often referred to the soft reboot era of Ninjago, with a new set of writers, changing animation studios, shortening episodes to 11 minutes, and dropping the "Masters of Spinjitzu" subtitle. Additionally, each season incorporates a certain Elemental theme dubbed "chapters." The Book of Elements refers to how each section dedicated to one Ninja's Elemental Power is referred to as a chapter.

The Elemental chapters thus far, in order, are Fire, Ice, Lightning, Earth, Energy, Water, Creation, and Destruction.

The seasons the arc is made up of are the Secrets of the Forbidden Spinjitzu, Prime Empire, Master of the Mountain, The Island, Seabound, Virtues of Spinjitzu, and Crystalized. It is tied with the Master Trials arc as the longest arc by installment count, with a total of seven.

It is preceded by the Oni Trilogy and succeeded by a new series.