Sweets sounds panicked and very, very confused. Also, a little scared. His voice is very quick to attack the speaker as soon as he's given the chance to speak.
"This is going to sound completely insane, believe me, but - something happened. Something really bad happened. One minute I was going through the profile I was putting together for you on that Robinson case, the next...I'm, uh..." There's a pause and it's glaringly obvious that Sweets is trying to figure out how to lay out his next statement. When he speaks again, he seems a little more than on the wary side. "My phone. It's out of service, for some unexplainable reason, I'm not in my office, and...and - I...I really think you should call me back."
Another awkward pause.
"Please?"
End message.
[ooc: NOTE - the only reason this call was able to go down is because, fortunately for Sweets here, Booth thought to get his hands on the same exact number he had back in their world.]