Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Episode | Broadcast date | Run time | Viewers (in millions) | Archive |
| --- | --- | --- | --- | --- |
| " Episode One " | 2November1968 | 24:32 | 7.3 | Only stills and/or fragments exist |
| " Episode Two " | 9November1968 | 24:26 | 7.1 | 16mm t/r |
| " Episode Three " | 16November1968 | 23:44 | 7.1 | 16mm t/r |
| " Episode Four " | 23November1968 | 24:18 | 6.4 | Only stills and/or fragments exist |
| " Episode Five " | 30November1968 | 23:25 | 6.7 | 16mm t/r |
| " Episode Six " | 7December1968 | 23:20 | 6.5 | 16mm t/r |
| " Episode Seven " | 14December1968 | 24:46 | 7.2 | 16mm t/r |
| " Episode Eight " | 21December1968 | 25:03 | 7.0 | 16mm t/r |
Question:
What episode had a run time of 24:18?
Answer:
" Episode Four "