Keep Out of the Everfree Forest

Nailed to the tree trunk was a bloodied, broken foreleg. The leg was bent at a 90 degree angle, with the sharp, splintered bones sticking out. They clicked against the tree with every gust of wind. The top of the leg was shredded. Blood ran down the tree trunk and formed small puddles in the dirt. There was no denying that this limb belonged to Mr. Cake.
Also nailed to the tree was a small note written in blood: “KEEP OUT OF THE FOREST”.
Emerald couldn’t believe what she was looking at. She let out a loud groan and passed out on the ground.
When Emerald came to, she was in her bedroom, breathing heavily. She stood up dizzily and ran straight into the lounge room, finding Sapphire sitting quietly on the couch.
“Oh, you’re up,” said Sapphire quietly.
Emerald laughed uneasily. “I just had the worst dream.”
“Sit down, Emerald,” said Sapphire. “It wasn’t a dream.”
“You’re right there.” Emerald chuckled. “That was a nightmare, not a dream.”
“Listen to me, Emerald!” Sapphire snapped. “You can call it whatever you like, but it was real. Mr. Cake is dead.”
Emerald sat down and hung her head in her hooves. “This can’t be happening. We’ve just arrived and now we’re part of a murder mystery!?”
Sapphire sighed. “Yes, Emerald. We are. We saw what we saw and we will never forget it. But he’s gone and there’s nothing we can do about it.”
Emerald stood up quickly. “You’re wrong,” she said firmly. “We can figure out what happened in that forest. We can find Mr. Cake’s killer.”
“No, Emerald,” Sapphire said. “Leave that to the police. Take another day off tomorrow and calm down. I’ll go see Pinkie and Mrs. Cake and see how they’re doing.”
Emerald sighed. “Okay, I’ll go see the chief tomorrow. Let him know what’s going on.”
Sapphire put a hoof on Emerald’s shoulder. “Trust me, by tomorrow, everypony in town will know what’s going on.”