T-Rex: Sherlock Holmes, who had recently been turned into a horse but was otherwise able to perform his duties as detective, whinnied.

T-Rex: There was a new mystery that required his attention!!

T-Rex: The mystery was on the third floor of a building, but only once Sherlock got up there did he realize that he couldn't get back down. The incline of the stairs was too steep for Horse Sherlock, and he couldn't see where his feet were going. It was really really scary.
T-Rex: "As a horse I find a ton of things really really scary," he muttered, annoyed and scared.

Utahraptor: I thought being a horse wasn't interfering with his detective work!
T-Rex: It wasn't!

T-Rex: For the CASE, he'd already deduced who did it. That part was easy peasy and not scary at all. But then a leaf hit the window and made the slightest noise and Sherlock, again terrified, trampled three men to death in the enclosed space.

T-Rex: Luckily he turned back into a dinosaur later - SINCE WE'RE ALL DINOSAURS - and the cops were on the lookout for a horse, so in many ways it was the perfect crime.
Off panel: How'd he turn back?
T-Rex: With much relief!
T-Rex: OBVIOUSLY??