Spellbook of summoning
The spellbook of summoning is a spellbook that appears exclusively in FIQHack. It weighs 40 aum and replaces the spellbook of create monster. When read, it allows you to learn the summon monster spell.
Summon monster is a clerical spell; when cast, the spell creates a random monster much like the spell of create monster, and the caster can select the square they are generated on. However, the monster will only be present for a limited amount of time, dependent on the caster's skill level - the monster will last for 5 turns at Unskilled level, 10 at Basic, 15 at Skilled, and 20 at Expert.
Aside from limited "lifespan", summoned monsters have other limits as well - summoned monsters will not generate with their usual monster starting inventory, do not leave a corpse, and do not benefit from lifesaving. Killing them does not give experience or alignment penalties or bonuses, and items they pick up will drop when they disappear. While a summoned monster can themselves summon other monsters, those monsters will disappear when their summoners do.