The Ultimate Vampire Resource and Directory

Jeff Slade is a detective with the CID department of the local police force led by Kate Grisham, although unusually for such a position he is an armed officer; carrying a handgun as routine. Slade is a good detective who gets results although his approach is somewhat maverick and his methods do leave a lot to be desired and have more than once landed him in trouble. Amongst Slade's colleagues at the department is science officer Holly Turner who has a secret that Slade manages to uncover. Holly owns a working Time Machine that was built by her late father. The machine is able to take Slade and Holly back far enough in time to witness a crime as it happens and discover who committed it. As a result Slade's track record with crime solving goes through the roof with case after case being solved in record time.
The rules of time travel in the series are as follows:
1. The time machine sends the traveler back in time by a random interval. Usually this is about a day but it may be as little as a few minutes or as much as a week. (N.B. In the final episode of the series it is found that the length of time traveled back can be controlled by altering the length of the photon rods; this is discovered by the research company Webb Biotech, who have also invented a time machine). However long you go back for, you must live through that time again (see rule 6).
2. You must not meet yourself in the past. It is not clear what would result if you did, but it is presumed the consequences would be dire.
3. You cannot change the past. One of the results of this restriction is that the effects of the time traveler's journey back in time are already visible "before" the journey is made.
4. You cannot exist more than twice in the same time frame. If you try to go back a second time, the machine will simply fail to operate.
5. When "in the past", you must get back to the time machine by the time you "left". Otherwise, you will be trapped in a "loop of infinity". This is what happened to Holly Turner's father. (This apparently conflicts with rule 2, as the time traveler would have to be at the machine at this moment, otherwise they couldn't have used it to travel into the past).
6. The time machine never travels into the future. Holly tells Jeff in the first episode "You can't travel into something that doesn't exist."