Vershab listens carefully to the lead curator before asking several questions: "What sort of fiend do you have on guard?"
"Are any magical spells one might use for research off limits?"
"Are there any sages who can help us with our research?"
Spoiler: Skill Checks
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Knowledge (Planes): (1d20+10)[21] regarding the fiendish guardian
Knowledge (Planes): (1d20+10)[18] regarding the Invisible Stalkers
As the party begins to descend he casts Detect Magic and begins scanning the doors, runes along the walls, and anything else that seems interesting. He does not allow himself to be too distracted by the Inner Sanctum's defenses, but he does make at least a cursory look (intending to determine how one might enter illicitly and avoid the worst of the defenses). Once in the book stacks he settles down to begin the research and begins directing the rest of the party to help, using liberal castings of Floating Disk.
Spoiler: Research Check
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Knowledge (Nobility): (1d20+9)[10]
Research "Damage" dealt: (1d8)[2]