Vying with her rival Tim for a promotion actuary Una finds herself on the back foot when her research - predictions about causes of death in seaside towns - fails to match the actual number of unusual deaths. There are some strange outliers in the data - death by hanging basket? - but even so the numbers have never let her down before. To make things worse Una's mum is getting re-married and Una is set against it. However when she learns that two of the deathly data points she's looking into were friends of her mum's new fiancé she decides to investigate. Soon a pattern emerges: if Una has interpreted the data correctly the next 'accidental' death will happen on the wedding day. Una will have to put her spreadsheets aside - and unite with her arch-nemesis Tim - to find out the truth hidden in the numbers.