#include <bits/stdc++.h>
#define oo 2100000000
using namespace std;

inline int read(){
    int x=0,f=1;char cc=getchar();
    while(cc<'0' || cc>'9') {if(cc=='-') f=-1;cc=getchar();}
    while(cc>='0' && cc<='9') {x=x*10+cc-'0';cc=getchar();}
    return x*f;
}

int n,m,x[410],y[410],xa,xb,ya,yb;
int x_[410],y_[410],xa_,xb_,ya_,yb_;
int sx[410],sy[410],gx[410],gy[410];
int numx,numy,tx[410][410],ty[410][410];
int con[200010],t[800010],nxt[800010],vis[200010];
double w[800010],dis[200010];

inline bool cmp1(int i,int j){
    return x[i]<x[j];
}

inline bool cmp2(int i,int j){
    return y[i]<y[j];
}

inline void ins(int x,int y,double z){
    m++;t[m]=y;w[m]=z;nxt[m]=con[x];con[x]=m;
    m++;t[m]=x;w[m]=z;nxt[m]=con[y];con[y]=m;
    //printf("%d %d %.5f\n",x,y,z);
}

int main(){
    for(int tt=read();tt;tt--){
        n=read();
        for(int i=1;i<=n;i++){
            x[2*i-1]=read();y[2*i-1]=read();
            x[2*i]=read();y[2*i]=read();
        }
        xa=read();ya=read();xb=read();yb=read();
        x[2*n+1]=xa;y[2*n+1]=ya;x[2*n+2]=xb;y[2*n+2]=yb;
        for(int i=1;i<=2*n+2;i++){
            sx[i]=i;sy[i]=i;
        }
        sort(sx+1,sx+2*n+3,cmp1);
        sort(sy+1,sy+2*n+3,cmp2);
        numx=0;numy=0;
        for(int i=1;i<=2*n+2;i++){
            numx++;x_[sx[i]]=numx;gx[numx]=x[sx[i]];
            while(i<2*n+2 && x[sx[i+1]]==x[sx[i]]){
                i++;x_[sx[i]]=numx;
            }
        }
        for(int i=1;i<=2*n+2;i++){
            numy++;y_[sy[i]]=numy;gy[numy]=y[sy[i]];
            while(i<2*n+2 && y[sy[i+1]]==y[sy[i]]){
                i++;y_[sy[i]]=numy;
            }
        }
        xa_=x_[2*n+1];ya_=y_[2*n+1];xb_=x_[2*n+2];yb_=y_[2*n+2];
        for(int i=1;i<=numx*numy;i++) con[i]=0;
        m=0;
        for(int i=1;i<=numx;i++)for(int j=1;j<=numy;j++){
            tx[i][j]=0;ty[i][j]=0;
        }
        for(int i=1;i<=n;i++){
            for(int j=x_[2*i-1];j<=x_[2*i];j++){tx[j][y_[2*i-1]]++;tx[j][y_[2*i]]--;}
            for(int j=y_[2*i-1];j<=y_[2*i];j++){ty[x_[2*i-1]][j]++;ty[x_[2*i]][j]--;}
        }
        for(int i=1;i<=numx;i++){
            int tmp=1;
            for(int j=1;j<numy;j++){
                tmp+=tx[i][j];ins((i-1)*numy+j,(i-1)*numy+j+1,(double)(gy[j+1]-gy[j])/tmp);
            }
        }
        for(int j=1;j<numy;j++){
            int tmp=1;
            for(int i=1;i<numx;i++){
                tmp+=ty[i][j];ins((i-1)*numy+j,i*numy+j,(double)(gx[i+1]-gx[i])/tmp);
            }
        }
        for(int i=1;i<=numx*numy;i++) dis[i]=oo;dis[(xa_-1)*numy+ya_]=0;
        for(int i=1;i<=numx*numy;i++) vis[i]=0;
        priority_queue<pair<double,int> > q;
        q.push(pair<double,int>(0,(xa_-1)*numy+ya_));
        while(!q.empty()){
            int x=q.top().second;q.pop();
            if(vis[x]) continue;vis[x]=1;
            for(int p=con[x];p;p=nxt[p])if(dis[x]+w[p]+1e-8<dis[t[p]]){
                dis[t[p]]=dis[x]+w[p];
                q.push(pair<double,int>(-dis[t[p]],t[p]));
            }
        }
        printf("%.5f\n",dis[(xb_-1)*numy+yb_]);
    }
}