Original sentence: In "Planet of the Ood", the Doctor gives a time frame for all three episodes: the 42nd century, during the Second Great and Bountiful Human Empire; the fourth incarnation of which was mentioned in "The Long Game" and "Bad Wolf".The Doctor is told again "his song is ending" in "Planet of the Dead".The red eye phenomenon is present in all three Ood episodes, as an effect of being possessed; in "The Impossible Planet" and "The Satan Pit" they were under the Beast's control.The reference to "Doctor-Donna" is clarified by the Doctor in "Journey's End"; also, reference is made to the disappearance of the bees, which is explained in "The Stolen Earth"
Edited sentence: In "Planet of the Ood", the Doctor gives a time frame for all three episodes: the 42nd century, during the Second Great and Bountiful Human Empire; the fourth incarnation of which was mentioned in The Long Game and Bad Wolf.The Doctor is told again "his song is ending" in Planet of the Dead.The red eye phenomenon is present in all three Ood episodes, as an effect of being possessed; in The Impossible Planet and The Satan Pit they were under the Beast's control.The reference to "Doctor-Donna" is clarified by the Doctor in Journey's End; also, reference is made to the disappearance of the bees, which is explained in "The Stolen Earth"