Maeterlinck felt that man's inner emotions were subordinate to the powerful external forces like fate and that man was pushed and pulled and controlled by these external forces like a puppet would be by a puppeteer. So when analysing the conflict in "The Intruder" what is more important is not the human emotions of the characters but the external forces which control them.
The dramatic tension is a result of an ailling mother who has given birth to a child and is not expected to live long. Much of the tension and the conflict arises because the blind grandfather-the father of the the dying mother-is able to perceive correctly the imminent death of his daughter, which the other sighted members of the family can't.
In fact, at the beginning of the play we expect the new born infant to die and not the mother. The uncle remarks, "It is now several weeks since he was born, and he has scarcely stirred. He has not cried once all the time! He is like a wax doll."
Throughout the play, the blind grandfather senses the ghost like presence of an intruder in the house: "It seems to me as if he were mowing inside the house." The reference is to the soud of someone sharpening a scythe to mow the grass with. It is late in the night and this is an obvious reference to the scythe which 'FatherTime' is sharpening to cut the thread of life of the ailing mother in the next room.
The play ends with the child crying and the announcement of the mother's death.