The potters take on a birthday tea set challenge, and a surprise second challenge that sees them making handleless milk jugs that must survive the bucket of doom.
The 11 remaining potters craft a keepsake box with a disguised lid before facing a surprise blindfold challenge.
It's Retro Week, and the remaining potters are taken back in time as they make a trio of flying birds and tackle an old-fashioned hot water bottle surprise challenge.
It's Raku Week, and the potters hope to impress the judges with their hanging planters. Series two semi-finalist Freya Bramble-Carter sets a challenge with a decorative flourish.
The remaining potters head for the roof to create gargoyles and chimney pots for expert guest judge Gabriel Nichols.
It's an illuminating week, as the potters make an embossed table light, before guest judge, fashion and lifestyle designer Henry Holland, really tests their decadent design skills.
The six remaining potters go wild as they create metallic-effect endangered animal sculptures fired in oil drums, before throwing a tall, thin-necked vase for a place in the quarter-final.
The remaining potters face an altered reality as they radically alter a coffee set and throw high-footed rice bowls. Whose shapeshifting creations will transport them to the semi-final?
It's a bathroom-themed semi-final as the potters make Turkish bath-style sinks and tiles and attempt Moorcroft tube lining.
The remaining potters create a stacking pyramid vase centrepiece and a daring sgraffito globe.