Frequency was a good movie, many moons ago. If done right that could be an interesting show.
Time travel seems to be this years new theme.
Shame we never got that mooted spin off from the excellent Duncan Jones movie Source Code. Been mooted for years but if it was ever going to happen it would be now.
Curious that there has been so much success from overlapping series in the US -
Chicago Fire, PD, Med and now Justice with goodness knows what else - maybe - Chicago Garbage Men - next up???
Then the interacting CSIs and Law and Orders and so on. Plus all the crossing over shows on CW - Flash, Arrow, Legends and now Supergirl joining the mix.
The BBC tried that with Casualty, Holby City and then Holby Blue that somehow flopped.
Wonder why this has become so popular and successful in the US but did not work here.
ITV had more luck with Heartbeat and The Royal but by and large we have not gone the route the US are doing.
ITV should try a similar drama franchise bringing back The Bill as Sun Hill Blues and then launch Sun Hill Fire (basically reviving London's Burning). And so on.
They had the opportunity all set up for such a scenario as the two shows were set close together but never did it.