If this does not work, a datu or a guru must be called in. The begu are not immortal, since death also rules in the land of the dead: a begu dies seven times before it is changed into a straw and finally becomes earth. The Batak believe that three categories of begu exist. The bicara guru are the begu of stillborn babies or of babies who have died before teething. It is possible to turn bicara guru into guardian spirits if misfortune has befallen the family of the child shortly after its death. With the help of a guru sibaso, the bicara guru can be made the family's guardian spirit for which a shrine is provided and to which sacrifices are regularly made. Once a year the bicara guru is accorded a special feast, preceded by ritual hair washing. The begu of members of the family who have had a sudden death (mate sada-uari) can also act as guardian spirits for the family. They include the victims of accidents, suicides, murder victims, or people struck by lightning. A shrine is built where they are venerated and where sacrifices are made. A third category consists of the begu of dead virgins (tungkup). Their graves, called bata-bata or ingan tungkup, are maintained for a long time by their relatives. Burial traditions Batak burial traditions are very rich and complex. Immediately after death various ritual actions are performed to make the begu understand that from now on its world is separate from that of its kin. Symbolically this is done by reversing the mat on which the corpse is laid out so that the body lies with its head at the foot of the mat. Thumbs and toes respectively are tied together and the body is rubbed all over with camphor and its orifices stopped with camphor, then it is wrapped in a white cotton cloth. During this perumah begu ceremony a guru sibaso declares to the begu of the deceased that it is definitely dead and must take leave of its relatives. Wealthier families have their coffins (Karo: pelangkah) made of the wood of the kemiri tree (Aleurites moluccanus), carved in the shape of a boat, its bow decorated with the carved head of a hornbill, or a horse, or a mythical beast known as a singa. The lid is then sealed with resin and the coffin may be placed in