 At Torchwood 's Cardiff headquarters , Owen determines from an autopsy that the alien that impregnated Gwen is a Nostrovite , a race of carnivorous shape shifters who hunt in pairs and mate for life . He tells Jack that after fertilisation , the female transfers her eggs to the male who plants them in a host body until they are ready to hatch . Later , the female kills the host to release the offspring . At the wedding venue , the female Nostrovite ( Colette Brown ) murders and partly devours wedding guest Mervyn . Toshiko investigates along with Rhys ' best man " Banana Boat " ( Jonathan Lewis Owen ) and they are subsequently captured by the alien , who intends to feed on them later . As Gwen and Rhys prepare to say their wedding vows , Jack runs up the aisle and demands that the wedding be halted . Owen and Ianto ( Gareth David @-@ Lloyd ) free Toshiko but the half @-@ eaten corpse of Mervyn is discovered by his wife , a bridesmaid , who alerts the entire wedding party to the murder . The Nostrovite reveals herself and is chased away by Jack , escaping through a window . 
 At Torchwood <a href='null_genetive' title='1'><mark>'s</mark></a>Cardiff headquarters , Owen <a href='uninflect' title='2'><mark>determines</mark></a> from an autopsy that the alien <a href='null_relcl' title='3'><mark>that</mark></a>impregnated Gwen <a href='drop_aux' title='4'><mark>is</mark></a>a Nostrovite , a race of carnivorous shape shifters <a href='null_relcl' title='5'><mark>who</mark></a>hunt in pairs and mate for life . He <a href='uninflect' title='6'><mark>tells</mark></a> Jack that after fertilisation , the female transfers her eggs to the male <a href='null_relcl' title='7'><mark>who</mark></a><a href='uninflect' title='8'><mark>plants</mark></a> them in a host body until they <a href='drop_aux' title='9'><mark>are</mark></a>ready to hatch . Later , the female <a href='uninflect' title='10'><mark>kills</mark></a> the host to release the offspring . At the wedding venue , the female Nostrovite ( Colette Brown ) murders and partly <a href='uninflect' title='11'><mark>devours</mark></a> wedding guest Mervyn . Toshiko <a href='uninflect' title='12'><mark>investigates</mark></a> along with Rhys <a href='null_genetive' title='13'><mark>'</mark></a>best man " Banana Boat " ( Jonathan Lewis Owen ) and they are subsequently captured by the alien , <a href='null_relcl' title='14'><mark>who</mark></a><a href='uninflect' title='15'><mark>intends</mark></a> to feed on them later . As Gwen and Rhys prepare to say their wedding vows , Jack <a href='uninflect' title='16'><mark>runs</mark></a> up the aisle and <a href='uninflect' title='17'><mark>demands</mark></a> that the wedding be halted . Owen and Ianto ( Gareth David @-@ Lloyd ) free Toshiko but the half @-@ eaten corpse of Mervyn is discovered by his wife , a bridesmaid , <a href='null_relcl' title='18'><mark>who</mark></a><a href='uninflect' title='19'><mark>alerts</mark></a> the entire wedding party to the murder . The Nostrovite <a href='uninflect' title='20'><mark>reveals</mark></a> herself and is chased away by Jack , escaping through a window . 
At Torchwood  Cardiff headquarters , Owen determine from an autopsy that the alien impregnated Gwen a Nostrovite , a race of carnivorous shape shifters hunt in pairs and mate fir life . He tell Jack that after fertilisation , the female transfers her eggs to the male plant em in a host body until they ready to hatch . Later , the female kill the host to release da offspring . At tdawedding venue , the female Nostrovite ( Colette Brown ) murders and partly devour wedding guest Mervyn . Toshiko investigate along with Rhys  best man " Banana Boat " ( Jonathan Lewis Owen ) and they r subsequently captured by the alien , intend to feed on themater . As Gwen and Rhys prepare to say their wedding vows , Jack run up thdaisle and demand that the wedding b halted . Owen and Ianto ( Gareth David @-@ Lloyd ) free Toshiko but the half @-@ eaten corpse of Mervyn is discovered by his wife , a bridesmaid , alert the entire wedding party to thedarder . The Nostrovite reveal herself and is chased away by Jack , escaping through a window .