The History and Essence of the Blazer\n\n The blazer's popularity spiked in Britain throughout the early 1960's and 1970's, as the mod culture flourished. Icons such as The Rolling Stones and The Beatles wore them in the music scene, and striped styles were particularly in vogue at the time.

Soon croquet clubs, rugby clubs, football clubs and clubs of all kinds wanted to get in on the blazer phenomenon. So by the 1890's, all flannel, loose-fitting casual jackets (which were generally brightly coloured at the time), became known as blazers. At the turn of the century, the blazer crossed the Atlantic.

In episode 6 Goodsir begins feeding Jacko the canned food and recording his observations. Later on Jacko goes crazy and ends up killing herself. Goodsir examines the corpse and discovers Jacko died of lead poisoning.

Some were oversealed and the lead dripped inside and gave lead poisoning to the food,  production designer Jonathan McKinstry said. Over the course of the series, that conjecture becomes less and less of a hypothesis and more of a reality for the various men aboard both the Terror and the Erebus.