It had been Frank Tripp on the phone, ringing about a suspicious package that had been delivered to CSI. The Bomb Squad had had to be called in to detonate it, although it later turned out to be a hoax. The news still managed to ruin Frankie's evening, as Horatio spent the rest of the night deep in thought, and she wasn't particularly happy about the night's event either.

What had been merely suspicious the night before became downright worrying the next day when they went into work. A letter had been delivered marked 'For the Attention of Horatio Caine.'

Frankie was in the break room, having coffee with the rest of the team when he wandered in, holding a sheet of paper and frowning. "What's that? A love letter from a secret admirer?" she joked.

"Hardly," he replied shortly, handing her a pair of latex gloves and then the letter. She read it through once in silence and then looked up at him, shocked.

"Is this genuine?"

"H, Frankie, come on! Don't keep us in suspense," Eric laughed.

"Lieutenant Caine," Frankie read, "I assume you know about me demonstration last night. I must say, the Bomb Squad's response was admirable. For the sake of the city, one can only hope they will be as impressive next time. The next package, I can assure you, will not be a hoax. As to where it will be delivered – well, you'll just have to wait and see. That's all it says," she finished, her eyes wide.

"What sort of sick joke is this?" Alexx snapped. "Who would think this is funny?"

"I don't think it is a joke Alexx," Horatio said quietly. "I think it's a warning."

"Why would he give us a warning?" Ryan asked.

"Most bombers are egotistical. They want people to know how clever they are. Eric, I want you to take the letter and envelope. I doubt you'll get much from the envelope, but it's worth a shot. Calleigh, take Ryan with you to finish up on the Edwards case. I have a feeling we're all going to be needed on this one before too long. Frankie, I know you don't have much to go on, but do you have enough to start profiling him?"

"I can make a start. As it's handwritten, I'll take it to a graphologist friend of mine, see what he thinks."

"Thanks," Horatio said, flashing her a brief smile. The next instant he was gone, followed by the other CSIs, leaving Alexx and Frankie alone.

"No rest for the wicked, I guess," Frankie sighed as she stood up.

"In this city? Forget it!"

Horatio glared at the various items in front of him. They told him nothing about the identity of the would-be bomber. Oh, he now knew that the man had used 2-inch screws – just the right length to set off the sensors – but these were a standard brand that could have been bought anywhere. They had been wrapped in some form of black plastic, and although it was difficult to be sure due to the controlled explosion, Horatio was fairly certain that it was from standard black garbage bags. The package itself had been destroyed, but a photo had been taken as it was scanned, and the post mark showed it had been posted at the Post Office on Collins Avenue. So utterly standard components, with no distinguishing marks, features or fingerprints, posted at one of the busiest branches in the city. Well, that was helpful.

Eric came in, looking as frustrated as he felt. "Get anything H?"

"Nothing useful. How about you?"

"Standard A4 paper from just about anywhere, posted in Downtown Miami. The envelope has been handled by God knows how many, but I asked Joseph to try to separate out the prints anyway. We may get lucky. Other than that – nothing."

"So unless Frankie comes up with a miracle, all we can do is wait for his next move." Horatio scowled unseeing into the middle distance, causing a young lab tech to turn pale and scurry past as quickly as possible. Eric stifled a grin. God help the bomber when Horatio caught up with him.