If the person dies, however, in a sudden or violent manner such as murder or suicide, if the proper rites have not been performed, or if they are influenced by powerful emotions such as a desire for revenge, love, jealousy, hatred or sorrow, the "reikon" is believed to transform into a "yūrei" which can then bridge the gap back to the physical world. The emotion or thought need not be particularly strong or driven. Even innocuous thoughts can cause a death to become disturbed. Once a thought enters the mind of a dying person, their "yūrei" will come back to complete the action last thought of before returning to the cycle of reincarnation.