One of many goofs...

... I love this show, but some of the plot holes and making-it-up-as-it-goes-along annoys me a bit. The one thing that really bugs me is that in the final episode, 'The Broken Crystal', Slade and Turner attempt to travel back but are only given three minutes by the machine. Slade says they can just wait the three minutes and travel back again, hopefully getting a bit longer. Holly says not possible, the three minutes are like a full stop and that this is another law of time that says they cannot exist in three time zones. Yet, in the first episode, Holly travels back to 9am that morning to help Slade. Later that afternoon, after returning to the present, she then demonstrates the machine to Slade and travels back 10 hours to 8:30 that morning, effectively existing in three time zones. Confusing!