If you want any information on current, past or future episodes, then you’ll find all you need to do here. Warning: the descriptions here may contain spoilers so, if you want to avoid knowing what happens the following week, then it is best to avoid this page.
(All details here belong to the BBC.)
Episode One (S1E1)
Episode Seven (S1E7)
Episode Eight (S1E8)
Episode Nine (S1E9)