"The so-called key is a guidepost to a planar passage!" The Headmaster patiently explained the basics to this group of exceptionally talented seedlings.
"The plane we occupy belongs to the Material Dimension, but the universe is vast. Many places contain unknown realms whose physical and magical laws are completely different from those of the Material Dimension. The creatures and basic materials within them are extremely valuable for research in our dimension. Summoning Department alchemists can communicate with creatures from other planes through complex Alchemy Arrays. Through equivalent exchanges, they can obtain material resources from other planes and even the services of creatures from other worlds. That's why Summoning Department alchemists have always been a popular profession throughout the universe."
When the Headmaster said this, the expressions of several Summoning Department instructors immediately improved. The more the Headmaster praised them now, the more advantageous it would be for them when competing for students later.
The Headmaster said, "But planar communication is highly unstable. Sometimes, even with the same Alchemy Array, different fluctuations in otherworldly energy at the time can produce different feedback. Thus, most summoners' communication with other worlds is unstable. With the same array, you might obtain the material you want the first time, only to summon something that wants you dead the next time!"
"What kind of thing?" Bing Guo asked instinctively.
"Many kinds..." The Headmaster said solemnly, "It could be some creature you're incapable of understanding, some kind of energy backlash, or even terrifying causal laws from another plane. There was once a case where a summoner used a large, sixteenth-level summoning array but summoned nothing at all. Yet a month later, every creature in the Life Star System where he lived died in various accidents. Across the entire star system, more than ten thousand inhabited planets and