Picture gallery
Finish the levels listed below to access the mentioned picture in the gallery.

War in Damara: Battlefield
Gemspark: Concept Art
Attack at Cedarleaf: Cedarleaf
The Wizard's Tower: Wizards Tower
The Jungles of Chult: Chult Jungle
The Yuan-Ti Temple: Chult Temple
Stand at Mithral Hall: Mithral
Into the Underdark: Githyanki Outpost
The Dragon's Lair: Dragon
The Lord of Chaos: Limbo

Secret books
Finish the following levels to access the mentioned secret book.

Attack at Cedarleaf: Zhai's Past
The Wizard's Tower: Khelben's Letter
The Jungles of Chult: Illius' Youth
The Yuan-Ti Temple: Nesme's Fall
Stand at Mithral Hall: Cireka's Vow Drizzt's Journal
Into the Underdark: Ygorl And The Dragon