Doctor Who has always been a serialized show. When the series began in 1963, stories were told in multiple-episode arcs, meaning an entire story could be told over multiple weeks. But when the series was rebooted in 2005, that shifted to a hybrid format: while there were season-long plotlines that would get set up in the premiere and not get resolved until the finale, episodes were more or less standalone adventures that could be watched on their own.
That creates an interesting tension — how do you balance the immediate threat at hand to whatever has been haunting the Doctor all season? That tightrope act can often be the deciding factor between a “meh” episode and an all-time great one. In 2014, this balance was struck perfectly by an often-overlooked episode that proved just how Doctor Who’s storytelling can be terrifying, heartbreaking, and wholesome all at once.
