Math Help Forum: Cook's Distance

Hello,

I have a little question, I ran a linear regression model, and got the following diagnostic plots from R (attached photo). It's crystal clear that observation 35 is an outlier, but I somehow fail to understand the last graph, how can I read the cook distance of this observation, what are these red lines for ?

can anyone help interpreting the graph ?

In case I am not clear, I do know what Cook's distance means, I just can't understand that graph, what is the Cook's distance of observation 35 and how do I read it ?

Thank You !